To provide the most up-to-date information, the revision of our documents on the World Wide Web will
be the most current. Your printed copy may be an earlier revision. To verify you have the latest information
available, refer to:
http://freescale.com
The following revision history table summarizes changes contained in this document.
Revision
Number
1.0007/14/2005Initial public release.
Revision
Date
Description of Changes
This product incorporates SuperFlash® technology licensed from SST.
Freescale‚ and the Freescale logo are trademarks of Freescale Semiconductor, Inc.
The MC9S08GBxxA/GTxxA are members of the low-cost, high-performance HCS08 Family of 8-bit
microcontroller units (MCUs). All MCUs in the family use the enhanced HCS08 core and are available
with a variety of modules, memory sizes, memory types, and package types.
1.2Features
Features have been organized to reflect:
•Standard features of the HCS08 Family
•Features of the MC9S08GBxxA/GTxxA MCU
1.2.1Standard Features of the HCS08 Family
•40-MHz HCS08 CPU (central processor unit)
•HC08 instruction set with added BGND instruction
•Background debugging system (see also Chapter 15, “Development Support”)
•Breakpoint capability to allow single breakpoint setting during in-circuit debugging (plus two more
breakpoints in on-chip debug module)
•Debug module containing two comparators and nine trigger modes. Eight deep FIFO for storing
change-of-flow addresses and event-only data. Debug module supports both tag and force
breakpoints.
•Support for up to 32 interrupt/reset sources
•Power-saving modes: wait plus three stops
•System protection features:
— Optional computer operating properly (COP) reset
— Low-voltage detection with reset or interrupt
— Illegal opcode detection with reset
— Illegal address detection with reset (some devices don’t have illegal addresses)
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor17
Chapter 1 Device Overview
1.2.2Features of MC9S08GBxxA/GTxxA Series of MCUs
•On-chip in-circuit programmable FLASH memory:
— Fully read/write functional across voltage and temperature ranges
— Block protection and security options
— (see Table 1-1 for device-specific information)
•On-chip random-access memory (RAM) (see Table 1-1 for device specific information)
•Two serial communications interface modules (SCI)
•Serial peripheral interface module (SPI)
•Multiple clock source options:
— Internally generated clock with ±0.2% trimming resolution and ±0.5% deviation across voltage
— Crystal
— Resonator
— External clock
•Inter-integrated circuit bus module to operate up to 100 kbps (IIC)
•One 3-channel and one 5-channel 16-bit timer/pulse width modulator (TPM) modules with
selectable input capture, output compare, and edge-aligned PWM capability on each channel. Each
timer module may be configured for buffered, centered PWM (CPWM) on all channels (TPMx).
•8-pin keyboard interrupt module (KBI)
•16 high-current pins (limited by package dissipation)
•Software selectable pullups on ports when used as input. Selection is on an individual port bit basis.
During output mode, pullups are disengaged.
•Internal pullup on
RESET and IRQ pin to reduce customer system cost
•Up to 56 general-purpose input/output (I/O) pins, depending on package selection
Note: Not all pins are bonded out in all packages. See Table 2-2 for complete details.
Block Diagaram Symbol Key:
= Not connected in 48- and 44-pin packages
= Not connected in 44-pin packages
Figure 1-1. MC9S08GBxxA/GTxxA Block Diagram
MC9S08GB60A Data Sheet, Rev. 1.00
20Freescale Semiconductor
Table 1-2 lists the functional versions of the on-chip modules.
Table 1-2. Block Versions
ModuleVersion
Analog-to-Digital Converter (ATD)3
Internal Clock Generator (ICG)2
Inter-Integrated Circuit (IIC)1
Keyboard Interrupt (KBI)1
Serial Communications Interface (SCI)1
Serial Peripheral Interface (SPI)3
Timer Pulse-Width Modulator (TPM)1
Central Processing Unit (CPU)2
1.4System Clock Distribution
Chapter 1 Device Overview
ICGERCLK
FFE
SYSTEM
CONTROL
LOGIC
RTI
TPM1TPM2IIC1SCI1SCI2SPI1
÷2
ICG
ICGOUT
ICGLCLK*
CPU
* ICGLCLK is the alternate BDC clock source for the MC9S08GBxxA/GTxxA.
FIXED FREQ CLOCK (XCLK)
÷2
BUSCLK
BDC
ATD1
ATD has min and max
frequency requirements. See
Chapter 1, “Device Overview” and
Appendix A, “Electrical Characteristics.
RAMFLASH
FLASH has frequency
requirements for program
and erase operation.
See Appendix A, “Electrical
Characteristics.
Figure 1-2. System Clock Distribution Diagram
Some of the modules inside the MCU have clock source choices. Figure 1-2 shows a simplified clock
connection diagram. The ICG supplies the clock sources:
•ICGOUT is an output of the ICG module. It is one of the following:
— The external crystal oscillator
— An external clock source
— The output of the digitally-controlled oscillator (DCO) in the frequency-locked loop
sub-module
Control bits inside the ICG determine which source is connected.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor21
Chapter 1 Device Overview
•FFE is a control signal generated inside the ICG. If the frequency of ICGOUT > 4 × the frequency
of ICGERCLK, this signal is a logic 1 and the fixed-frequency clock will be the ICGERCLK.
Otherwise the fixed-frequency clock will be BUSCLK.
•ICGLCLK — Development tools can select this internal self-clocked source (~ 8 MHz) to speed
up BDC communications in systems where the bus clock is slow.
•ICGERCLK — External reference clock can be selected as the real-time interrupt clock source.
MC9S08GB60A Data Sheet, Rev. 1.00
22Freescale Semiconductor
Chapter 2
Pins and Connections
2.1Introduction
This section describes signals that connect to package pins. It includes a pinout diagram, a table of signal
properties, and detailed discussion of signals.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor23
Chapter 2 Pins and Connections
2.2Device Pin Assignment
RESET
PTG7
PTC0/TxD2
PTC1/RxD2
PTC2/SDA1
PTC3/SCL1
PTC4
PTC5
PTC6
PTG6
PTG5
PTG4
64
63 62 61
1
2
3
4
5
6
7
8
9
PTG2/EXTAL
PTG3
60
PTG0/BKGD/MS
PTG1/XTAL
58
59
57
SSAD
V
56
DDAD
V
PTF1
PTF0
PTA7/KBI1P7
PTA5/KBI1P5
PTA6/KBI1P6
PTA4/KBI1P4
505152535455
PTA3/KBI1P3
49
48
47
46
45
44
43
42
41
40
PTA2/KBI1P2
PTA1/KBI1P1
PTA0/KBI1P0
PTF7
PTF6
PTF5
V
REFL
V
REFH
PTB7/AD1P7
PTC7
PTF2
PTF3
PTF4
PTE0/TxD1
PTE1/RxD1
IRQ
10
11
12
13
14
15
16
27
26
PTD0/TPM1CH0
PTD1/TPM1CH1
17
PTE2/SS1
19
18
PTE3/MISO1
PTE4/MOSI1
20 21 22
PTE6
PTE5/SPSCK1
23
PTE7
24
25
SS
DD
V
V
Figure 2-1. MC9S08GBxxA in 64-Pin LQFP Package
28 29 30 31
PTD2/TPM1CH2
PTD4/TPM2CH1
PTD3/TPM2CH0
39
38
37
36
35
34
32
PTD6/TPM2CH3
PTD5/TPM2CH2
PTD7/TPM2CH4
PTB6/AD1P6
PTB5/AD1P5
PTB4/AD1P4
PTB3/AD1P3
PTB2/AD1P2
PTB1/AD1P1
PTB0/AD1P0
33
MC9S08GB60A Data Sheet, Rev. 1.00
24Freescale Semiconductor
RESET
PTC0/TxD2
PTC1/RxD2
PTC2/SDA1
PTC3/SCL1
PTC4
PTC5
PTC6
PTC7
PTE0/TxD1
PTE1/RxD1
IRQ
Chapter 2 Pins and Connections
DDAD
SSAD
PTG2/EXTAL
PTG1/XTAL
PTG3
47
48
1
PTG0/BKGD/MS
46
45
V
V
44
43
PTA6/KBI1P6
PTA7/KBI1P7
42
41
2
3
4
5
6
7
8
9
10
11
12
14
15
16
17
18
19
13
20
PTA4/KBI1P4
PTA5/KBI1P5
40
21
PTA3/KBI1P3
39
38
22
23
PTA2/KBI1P2
37
PTA1/KBI1P1
36
PTA0/KBI1P0
35
V
34
REFL
V
33
REFH
PTB7/AD1P7
32
PTB6/AD1P6
31
PTB5/AD1P5
30
PTB4/AD1P4
29
PTB3/AD1P3
28
PTB2/AD1P2
27
PTB1/AD1P1
26
PTB0/AD1P0
25
24
SS1
SS1
V
SS2
V
DD
V
PTE2/
PTE3/MISO1
PTE5/SPSCK1
PTE4/MOSI1
PTD1/TPM1CH1
PTD0/TPM1CH0
PTD2/TPM1CH2
PTD3/TPM2CH0
PTD4/TPM2CH1
Figure 2-2. MC9S08GTxxA in 48-Pin QFN Package
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor25
Chapter 2 Pins and Connections
RESET
PTC0/TxD2
PTC1/RxD2
PTC2/SDA1
PTC3/SCL1
PTC4
PTC5
PTC6
PTE0/TxD1
PTE1/RxD1
IRQ
1
11
PTG2/EXTAL
44
2
3
4
5
6
7
8
9
10
12
SS1
PTG1/XTAL
PTG0/BKGD/MS
43
42
13
14
SSAD
V
41
15
DDAD
V
PTA7/KBI1P7
40
16
17
SS
DD
V
V
PTA6/KBI1P6
39
38
18
PTA4/KBI1P4
PTA5/KBI1P5
37
19
PTA3/KBI1P3
36
35
20
21
PTA2/KBI1P2
34
PTA1/KBI1P1
33
PTA0/KBI1P0
32
V
31
30
29
28
27
26
25
24
22
REFL
V
REFH
PTB7/AD1P7
PTB6/AD1P6
PTB5/AD1P5
PTB4/AD1P4
PTB3/AD1P3
PTB2/AD1P2
PTB1/AD1P1
23
PTE2/
PTE3/MISO1
PTE4/MOSI1
PTE5/SPSCK1
PTD1/TPM1CH1
PTD0/TPM1CH0
PTD3/TPM2CH0
PTB0/AD1P0
PTD4/TPM2CH1
Figure 2-3. MC9S08GTxxA in 44-Pin QFP Package
2.3Recommended System Connections
Figure 2-4 shows pin connections that are common to almost all MC9S08GBxxA application systems.
MC9S08GTxxA connections will be similar except for the number of I/O pins available. A more detailed
discussion of system connections follows.
MC9S08GB60A Data Sheet, Rev. 1.00
26Freescale Semiconductor
SYSTEM
POWER
NOTE 1
C1
BACKGROUND HEADER
V
DD
OPTIONAL
MANUAL
RESET
+
C
3 V
BLK
10 µF
X1
ASYNCHRONOUS
INTERRUPT
INPUT
V
DD
+
R
F
V
C
BY
0.1 µF
C2
DD
4.7 kΩ–10 kΩ
0.1 µF
C
BYAD
0.1 µF
R
S
V
DD
4.7 kΩ–10 kΩ
0.1 µF
V
REFH
V
DDAD
MC9S08GBxxA/GTxxA
V
SSAD
V
REFL
V
DD
V
SS
NOTE 4
XTAL
NOTE 2
EXTAL
NOTE 2
BKGD/MS
NOTE 3
RESET
NOTE 5
IRQ
NOTE 5
PORT
A
PORT
B
PORT
C
Chapter 2 Pins and Connections
PTA0/KBI1P0
PTA1/KBI1P1
PTA2/KBI1P2
PTA3/KBI1P3
PTA4/KBI1P4
PTA5/KBI1P5
PTA6/KBI1P6
PTA7/KBI1P7
PTB0/AD1P0
PTB1/AD1P1
PTB2/AD1P2
PTB3/AD1P3
PTB4/AD1P4
PTB5/AD1P5
PTB6/AD1P6
PTB7/AD1P7
PTC0/TxD2
PTC1/RxD2
PTC2/SDA1
PTC3/SCL1
I/O AND
PERIPHERAL
INTERFACE TO
APPLICATION
SYSTEM
PTC4
PTC5
PTC6
PTC7
PTD0/TPM1CH0
PTD1/TPM1CH1
PTD2/TPM1CH2
PTD3/TPM2CH0
PTD4/TPM2CH1
PTD5/TPM2CH2
PTD6/TPM2CH3
PTD7/TPM2CH4
PTE0/TxD1
PTE1/RxD1
PTE2/
SS1
PTE3/MISO1
PTE4/MOSI1
PTE5/SPSCK1
PTE6
PTE7
NOTES:
1. Not required if using the
internal oscillator option.
2. These are the same pins as
PTG1 and PTG2.
3. BKGD/MS is the same pin
as PTG0.
4. The 48-pin QFN has 2 V
pins (V
of which must beconnected
SS1
and V
SS2
to GND.
5. RC filters on
RESET and
IRQ are recommended for
EMC-sensitive applications
SS
), both
PTG0/BKDG/MS
PTG1/XTAL
PTG2/EXTAL
PTG3
PTG4
PTG5
PTG6
PTG7
PTF0
PTF1
PTF2
PTF3
PTF4
PTF5
PTF6
PTF7
PORT
G
PORT
F
PORT
D
PORT
E
Figure 2-4. Basic System Connections
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor27
Chapter 2 Pins and Connections
2.3.1Power
VDD and VSS are the primary power supply pins for the MCU. This voltage source supplies power to all
I/O buffer circuitry and to an internal voltage regulator. The internal voltage regulator provides regulated
lower-voltage source to the CPU and other internal circuitry of the MCU.
Typically, application systems have two separate capacitors across the power pins. In this case, there
should be a bulk electrolytic capacitor, such as a 10-µF tantalum capacitor, to provide bulk charge storage
for the overall system and a 0.1-µF ceramic bypass capacitor located as close to the MCU power pins as
practical to suppress high-frequency noise.
V
DDAD
and V
are the analog power supply pins for the MCU. This voltage source supplies power to
SSAD
the ATD. A 0.1-µF ceramic bypass capacitor should be located as close to the MCU power pins as practical
to suppress high-frequency noise.
2.3.2Oscillator
Out of reset, the MCU uses an internally generated clock (self-clocked mode — f
Self_reset
approximately equivalent to an 8-MHz crystal rate. This frequency source is used during reset startup and
can be enabled as the clock source for stop recovery to avoid the need for a long crystal startup delay. This
MCU also contains a trimmable internal clock generator (ICG) module that can be used to run the MCU.
For more information on the ICG, see Chapter 7, “Internal Clock Generator (S08ICGV2).”
The oscillator in this MCU is a Pierce oscillator that can accommodate a crystal or ceramic resonator in
either of two frequency ranges selected by the RANGE bit in the ICGC1 register. Rather than a crystal or
ceramic resonator, an external oscillator can be connected to the EXTAL input pin, and the XTAL output
pin can be used as general I/O.
Refer to Figure 2-4 for the following discussion. R
(when used) and RF should be low-inductance
S
resistors such as carbon composition resistors. Wire-wound resistors, and some metal film resistors, have
too much inductance. C1 and C2 normally should be high-quality ceramic capacitors that are specifically
designed for high-frequency applications.
is used to provide a bias path to keep the EXTAL input in its linear range during crystal startup and its
R
F
value is not generally critical. Typical systems use 1 MΩ to 10 MΩ. Higher values are sensitive to humidity
and lower values reduce gain and (in extreme cases) could prevent startup.
), that is
C1 and C2 are typically in the 5-pF to 25-pF range and are chosen to match the requirements of a specific
crystal or resonator. Be sure to take into account printed circuit board (PCB) capacitance and MCU pin
capacitance when sizing C1 and C2. The crystal manufacturer typically specifies a load capacitance which
is the series combination of C1 and C2 which are usually the same size. As a first-order approximation,
use 10 pF as an estimate of combined pin and PCB capacitance for each oscillator pin (EXTAL and
XTAL).
2.3.3Reset
RESET is a dedicated pin with a pullup device built in. It has input hysteresis, a high current output driver,
and no output slew rate control. Internal power-on reset and low-voltage reset circuitry typically make
external reset circuitry unnecessary. This pin is normally connected to the standard 6-pin background
MC9S08GB60A Data Sheet, Rev. 1.00
28Freescale Semiconductor
Chapter 2 Pins and Connections
debug connector so a development system can directly reset the MCU system. If desired, a manual external
reset can be added by supplying a simple switch to ground (pull reset pin low to force a reset).
Whenever any reset is initiated (whether from an external signal or from an internal system), the reset pin
is driven low for approximately 34 cycles of f
cycles of f
Self_reset
later. If reset was caused by an internal source such as low-voltage reset or watchdog
Self_reset
, released, and sampled again approximately 38
timeout, the circuitry expects the reset pin sample to return a logic 1. The reset circuitry decodes the cause
of reset and records it by setting a corresponding bit in the system control reset status register (SRS).
In EMC-sensitive applications, an external RC filter is recommended on the reset pin. See Figure 2-4 for
an example.
2.3.4Background / Mode Select (PTG0/BKGD/MS)
The background/mode select (BKGD/MS) shares its function with an I/O port pin. While in reset, the pin
functions as a mode select pin. Immediately after reset rises the pin functions as the background pin and
can be used for background debug communication. While functioning as a background/mode select pin,
the pin includes an internal pullup device, input hysteresis, a standard output driver, and no output slew
rate control. When used as an I/O port (PTG0) the pin is limited to output only.
If nothing is connected to this pin, the MCU will enter normal operating mode at the rising edge of reset.
If a debug system is connected to the 6-pin standard background debug header, it can hold BKGD/MS low
during the rising edge of reset which forces the MCU to active background mode.
The BKGD pin is used primarily for background debug controller (BDC) communications using a custom
protocol that uses 16 clock cycles of the target MCU’s BDC clock per bit time. The target MCU’s BDC
clock could be as fast as the bus clock rate, so there should never be any significant capacitance connected
to the BKGD/MS pin that could interfere with background serial communications.
Although the BKGD pin is a pseudo open-drain pin, the background debug communication protocol
provides brief, actively driven, high speedup pulses to ensure fast rise times. Small capacitances from
cables and the absolute value of the internal pullup device play almost no role in determining rise and fall
times on the BKGD pin.
2.3.5General-Purpose I/O and Peripheral Ports
The remaining 55 pins are shared among general-purpose I/O and on-chip peripheral functions such as
timers and serial I/O systems. (17 of these pins are not bonded out on the 48-pin package, 20 of these pins
are not bonded out on the 44-pin package.) Immediately after reset, all 55 of these pins are configured as
high-impedance general-purpose inputs with internal pullup devices disabled.
NOTE
To prevent extra current drain from floating input pins, the reset
initialization routine in the application program should either enable
on-chip pullup devices or change the direction of unused pins to outputs so
the pins do not float.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor29
Chapter 2 Pins and Connections
For information about controlling these pins as general-purpose I/O pins, see Chapter 6, “Parallel
Input/Output.” For information about how and when on-chip peripheral systems use these pins, refer to the
appropriate section from Table 2-1.
Table 2-1. Pin Sharing References
Port Pins
PTA7–PTA0KBI1P7–KBI1P0Chapter 2, “Pins and Connections”
See this section for information about modules that share these pins.
When an on-chip peripheral system is controlling a pin, data direction control bits still determine what is
read from port data registers even though the peripheral module controls the pin direction by controlling
the enable for the pin’s output buffer. See Chapter 6, “Parallel Input/Output” for details.
Pullup enable bits for each input pin control whether on-chip pullup devices are enabled whenever the pin
is acting as an input even if it is being controlled by an on-chip peripheral module. When the PTA7–PTA4
pins are controlled by the KBI module and are configured for rising-edge/high-level sensitivity, the pullup
enable control bits enable pulldown devices rather than pullup devices. Similarly, when IRQ is configured
as the IRQ input and is set to detect rising edges, the pullup enable control bit enables a pulldown device
rather than a pullup device.
MC9S08GB60A Data Sheet, Rev. 1.00
30Freescale Semiconductor
Chapter 2 Pins and Connections
2.3.6Signal Properties Summary
Table 2-2 summarizes I/O pin characteristics. These characteristics are determined by the way the
common pin interfaces are hardwired to internal circuits.
Table 2-2. Signal Properties
Pin
Name
V
DD
V
SS
V
DDAD
V
SSAD
V
REFH
V
REFL
Dir
High Current
Pin
Output
Slew
Pull-Up
1
———
———
———
———
———
———
2
Comments
The 48-pin QFN package has two V
and V
SS2
.
RESETI/OYNYPin contains integrated pullup.
IRQPE must be set to enable IRQ function.
IRQ does not have a clamp diode to V
IRQ
not be driven above V
I— — Y
Pullup/pulldown active when IRQ pin function
DD
enabled. Pullup forced on when IRQ enabled for
falling edges; pulldown forced on when IRQ enabled
for rising edges.
PTA0/KBI1P0I/ONSWCSWC
PTA1/KBI1P1I/ONSWCSWC
PTA2/KBI1P2I/ONSWCSWC
PTA3/KBI1P3I/ONSWCSWC
PTA4/KBI1P4I/ONSWCSWC
PTA5/KBI1P5I/ONSWCSWC
PTA6/KBI1P6I/ONSWCSWC
PTA7/KBI1P7I/ONSWCSWC
Pullup/pulldown active when KBI pin function
enabled. Pullup forced on when KBI1Px enabled for
falling edges; pulldown forced on when KBI1Px
enabled for rising edges.
PTB0/AD1P0I/ONSWCSWC
PTB1/AD1P1I/ONSWCSWC
PTB2/AD1P2I/ONSWCSWC
PTB3/AD1P3I/ONSWCSWC
PTB4/AD1P4I/ONSWCSWC
PTB5/AD1P5I/ONSWCSWC
PTB6/AD1P6I/ONSWCSWC
PTB7/AD1P7I/ONSWCSWC
PTC0/TxD2I/OYSWCSWC
PTC1/RxD2I/OYSWCSWC
When pin is configured for SCI function, pin is
configured for partial output drive.
PTC2/SDA1I/OYSWCSWC
PTC3/SCL1I/OYSWCSWC
PTC4I/OYSWCSWC
PTC5I/OYSWCSWC
PTC6I/OYSWCSWC
pins — V
SS
. IRQ should
DD
SS1
.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor31
Chapter 2 Pins and Connections
Table 2-2. Signal Properties (continued)
Pin
Name
Dir
High Current
Pin
Output
Slew
Pull-Up
1
2
Comments
PTC7I/OYSWCSWCNot available on 44-pin pkg
PTD0/TPM1CH0I/ONSWCSWC
PTD1/TPM1CH1I/ONSWCSWC
PTD2/TPM1CH2I/ONSWCSWCNot available on 44-pin pkg
PTD3/TPM2CH0I/ONSWCSWC
PTD4/TPM2CH1I/ONSWCSWC
PTD5/TPM2CH2I/ONSWCSWCNot available on 44-, or 48-pin pkg
PTD6/TPM2CH3I/ONSWCSWCNot available on 44-, or 48-pin pkg
PTD7/TPM2CH4I/ONSWCSWCNot available on 44-, or 48-pin pkg
PTE0/TxD1I/ONSWCSWC
PTE1/RxD1I/ONSWCSWC
SS1I/ONSWCSWC
PTE2/
PTE3/MISO1I/ONSWCSWC
PTE4/MOSI1I/ONSWCSWC
PTE5/SPSCK1I/ONSWCSWC
PTE6I/ONSWCSWCNot available on 44-, or 48-pin pkg
PTE7I/ONSWCSWCNot available on 44-, or 48-pin pkg
PTF0I/OYSWCSWCNot available on 44-, or 48-pin pkg
PTF1I/OYSWCSWCNot available on 44-, or 48-pin pkg
PTF2I/OYSWCSWCNot available on 44-, or 48-pin pkg
PTF3I/OYSWCSWCNot available on 44-, or 48-pin pkg
PTF4I/OYSWCSWCNot available on 44-, or 48-pin pkg
PTF5I/OYSWCSWCNot available on 44-, or 48-pin pkg
PTF6I/OYSWCSWCNot available on 44-, or 48-pin pkg
PTF7I/OYSWCSWCNot available on 44-, or 48-pin pkg
PTG0/BKGD/MSONSWCSWC
PTG1/XTALI/ONSWCSWC
PTG2/EXTALI/ONSWCSWC
Pullup enabled and slew rate disabled when BDM
function enabled.
Pullup and slew rate disabled when XTAL pin
function.
Pullup and slew rate disabled when EXTAL pin
function.
PTG3I/ONSWCSWCNot available on 44-pin pkg
PTG4I/ONSWCSWCNot available on 44-, or 48-pin pkg
PTG5I/ONSWCSWCNot available on 44-, or 48-pin pkg
PTG6I/ONSWCSWCNot available on 44-, or 48-pin pkg
PTG7I/ONSWCSWCNot available on 44-, or 48-pin pkg
1
SWC is software controlled slew rate, the register is associated with the respective port.
2
SWC is software controlled pullup resistor, the register is associated with the respective port.
MC9S08GB60A Data Sheet, Rev. 1.00
32Freescale Semiconductor
Chapter 3
Modes of Operation
3.1Introduction
The operating modes of the MC9S08GBxxA/GTxxA are described in this section. Entry into each mode,
exit from each mode, and functionality while in each of the modes are described.
3.2Features
•Active background mode for code development
•Wait mode:
— CPU shuts down to conserve power
— System clocks running
— Full voltage regulation maintained
•Stop modes:
— System clocks stopped; voltage regulator in standby
— Stop1 — Full power down of internal circuits for maximum power savings
— Stop2 — Partial power down of internal circuits, RAM contents retained
— Stop3 — All internal circuits powered for fast recovery
3.3Run Mode
This is the normal operating mode for the MC9S08GBxxA/GTxxA. This mode is selected when the
BKGD/MS pin is high at the rising edge of reset. In this mode, the CPU executes code from internal
memory with execution beginning at the address fetched from memory at 0xFFFE:0xFFFF after reset.
3.4Active Background Mode
The active background mode functions are managed through the background debug controller (BDC) in
the HCS08 core. The BDC, together with the on-chip debug module (DBG), provide the means for
analyzing MCU operation during software development.
Active background mode is entered in any of five ways:
•When the BKGD/MS pin is low at the rising edge of reset
•When a BACKGROUND command is received through the BKGD pin
•When a BGND instruction is executed
•When encountering a BDC breakpoint
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor33
Chapter 3 Modes of Operation
•When encountering a DBG breakpoint
After entering active background mode, the CPU is held in a suspended state waiting for serial background
commands rather than executing instructions from the user’s application program.
Background commands are of two types:
•Non-intrusive commands, defined as commands that can be issued while the user program is
running. Non-intrusive commands can be issued through the BKGD pin while the MCU is in run
mode; non-intrusive commands can also be executed while the MCU is in the active background
mode. Non-intrusive commands include:
•Active background commands, which can be executed only while the MCU is in active background
mode. Active background commands include commands to:
— Read or write CPU registers
— Trace one user program instruction at a time
— Leave active background mode to return to the user’s application program (GO)
The active background mode is used to program a bootloader or user application program into the FLASH
program memory before the MCU is operated in run mode for the first time. When the
MC9S08GBxxA/GTxxA is shipped from the Freescale Semiconductor factory, the FLASH program
memory is erased by default unless specifically noted so there is no program that could be executed in run
mode until the FLASH memory is initially programmed. The active background mode can also be used to
erase and reprogram the FLASH memory after it has been previously programmed.
For additional information about the active background mode, refer to Chapter 15, “Development Support.
3.5Wait Mode
Wait mode is entered by executing a WAIT instruction. Upon execution of the WAIT instruction, the CPU
enters a low-power state in which it is not clocked. The I bit in CCR is cleared when the CPU enters the
wait mode, enabling interrupts. When an interrupt request occurs, the CPU exits the wait mode and
resumes processing, beginning with the stacking operations leading to the interrupt service routine.
While the MCU is in wait mode, there are some restrictions on which background debug commands can
be used. Only the BACKGROUND command and memory-access-with-status commands are available
when the MCU is in wait mode. The memory-access-with-status commands do not allow memory access,
but they report an error indicating that the MCU is in either stop or wait mode. The BACKGROUND
command can be used to wake the MCU from wait mode and enter active background mode.
3.6Stop Modes
One of three stop modes is entered upon execution of a STOP instruction when the STOPE bit in the
system option register is set. In all stop modes, all internal clocks are halted. If the STOPE bit is not set
MC9S08GB60A Data Sheet, Rev. 1.00
34Freescale Semiconductor
Chapter 3 Modes of Operation
when the CPU executes a STOP instruction, the MCU will not enter any of the stop modes and an illegal
opcode reset is forced. The stop modes are selected by setting the appropriate bits in SPMSC2.
Table 3-1 summarizes the behavior of the MCU in each of the stop modes.
Table 3-1. Stop Mode Behavior
CPU, Digital
ModePDCPPDC
Peripherals,
FLASH
RAMICGATDRegulatorI/O PinsRTI
Stop110OffOffOffDisabled
Stop211OffStandbyOffDisabledStandbyStates
Stop30Don’t
care
1
Either ATD stop mode or power-down mode depending on the state of ATDPU.
2
Crystal oscillator can be configured to run in stop3. Please see the ICG registers.
StandbyStandbyOff
2
DisabledStandbyStates
1
OffResetOff
Optionally on
held
Optionally on
held
3.6.1Stop1 Mode
The stop1 mode provides the lowest possible standby power consumption by causing the internal circuitry
of the MCU to be powered down. Stop1 can be entered only if the LVD circuit is not enabled in stop modes
(either LVDE or LVDSE not set).
When the MCU is in stop1 mode, all internal circuits that are powered from the voltage regulator are turned
off. The voltage regulator is in a low-power standby state, as is the ATD.
Exit from stop1 is performed by asserting either of the wake-up pins on the MCU:
always an active low input when the MCU is in stop1, regardless of how it was configured before entering
stop1.
Entering stop1 mode automatically asserts LVD. Stop1 cannot be exited until V
must rise above the LVI rearm voltage).
RESET or IRQ. IRQ is
DD
>V
LVDH/L
rising (V
DD
Upon wake-up from stop1 mode, the MCU will start up as from a power-on reset (POR). The CPU will
take the reset vector.
3.6.2Stop2 Mode
The stop2 mode provides very low standby power consumption and maintains the contents of RAM and
the current state of all of the I/O pins. Stop2 can be entered only if the LVD circuit is not enabled in stop
modes (either LVDE or LVDSE not set).
Before entering stop2 mode, the user must save the contents of the I/O port registers, as well as any other
memory-mapped registers they want to restore after exit of stop2, to locations in RAM. Upon exit of stop2,
these values can be restored by user software before pin latches are opened.
When the MCU is in stop2 mode, all internal circuits that are powered from the voltage regulator are turned
off, except for the RAM. The voltage regulator is in a low-power standby state, as is the ATD. Upon entry
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor35
Chapter 3 Modes of Operation
into stop2, the states of the I/O pins are latched. The states are held while in stop2 mode and after exiting
stop2 mode until a 1 is written to PPDACK in SPMSC2.
Exit from stop2 is performed by asserting either of the wake-up pins:
RESET or IRQ, or by an RTI
interrupt. IRQ is always an active low input when the MCU is in stop2, regardless of how it was configured
before entering stop2.
Upon wake-up from stop2 mode, the MCU will start up as from a power-on reset (POR) except pin states
remain latched. The CPU will take the reset vector. The system and all peripherals will be in their default
reset states and must be initialized.
After waking up from stop2, the PPDF bit in SPMSC2 is set. This flag may be used to direct user code to
go to a stop2 recovery routine. PPDF remains set and the I/O pin states remain latched until a 1 is written
to PPDACK in SPMSC2.
To maintain I/O state for pins that were configured as general-purpose I/O, the user must restore the
contents of the I/O port registers, which have been saved in RAM, to the port registers before writing to
the PPDACK bit. If the port registers are not restored from RAM before writing to PPDACK, then the
register bits will assume their reset states when the I/O pin latches are opened and the I/O pins will switch
to their reset states.
For pins that were configured as peripheral I/O, the user must reconfigure the peripheral module that
interfaces to the pin before writing to the PPDACK bit. If the peripheral module is not enabled before
writing to PPDACK, the pins will be controlled by their associated port control registers when the I/O
latches are opened.
3.6.3Stop3 Mode
Upon entering the stop3 mode, all of the clocks in the MCU, including the oscillator itself, are halted. The
ICG is turned off, the ATD is disabled, and the voltage regulator is put in standby. The states of all of the
internal registers and logic, as well as the RAM content, are maintained. The I/O pin states are not latched
at the pin as in stop2. Instead they are maintained by virtue of the states of the internal logic driving the
pins being maintained.
Exit from stop3 is performed by asserting
interrupt. The asynchronous interrupt pins are the IRQ or KBI pins.
If stop3 is exited by means of the
RESET pin, then the MCU will be reset and operation will resume after
taking the reset vector. Exit by means of an asynchronous interrupt or the real-time interrupt will result in
the MCU taking the appropriate interrupt vector.
A separate self-clocked source (≈1 kHz) for the real-time interrupt allows a wakeup from stop2 or stop3
mode with no external components. When RTIS2:RTIS1:RTIS0 = 0:0:0, the real-time interrupt function
and this 1-kHz source are disabled. Power consumption is lower when the 1-kHz source is disabled, but in
that case the real-time interrupt cannot wake the MCU from stop.
RESET, an asynchronous interrupt pin, or through the real-time
MC9S08GB60A Data Sheet, Rev. 1.00
36Freescale Semiconductor
Chapter 3 Modes of Operation
3.6.4Active BDM Enabled in Stop Mode
Entry into the active background mode from run mode is enabled if the ENBDM bit in BDCSCR is set.
This register is described in the Chapter 15, “Development Support,” section of this data sheet. If ENBDM
is set when the CPU executes a STOP instruction, the system clocks to the background debug logic remain
active when the MCU enters stop mode so background debug communication is still possible. In addition,
the voltage regulator does not enter its low-power standby state but maintains full internal regulation. If
the user attempts to enter either stop1 or stop2 with ENBDM set, the MCU will instead enter stop3.
Most background commands are not available in stop mode. The memory-access-with-status commands
do not allow memory access, but they report an error indicating that the MCU is in either stop or wait
mode. The BACKGROUND command can be used to wake the MCU from stop and enter active
background mode if the ENBDM bit is set. After the device enters background debug mode, all
background commands are available. The table below summarizes the behavior of the MCU in stop when
entry into the background debug mode is enabled.
Table 3-2. BDM Enabled Stop Mode Behavior
CPU, Digital
ModePDCPPDC
Peripherals,
FLASH
RAMICGATDRegulatorI/O PinsRTI
Stop3Don’t
care
1
Either ATD stop mode or power-down mode depending on the state of ATDPU.
Don’t
care
StandbyStandbyActiveDisabled
1
ActiveStates
Optionally on
held
3.6.5LVD Enabled in Stop Mode
The LVD system is capable of generating either an interrupt or a reset when the supply voltage drops below
the LVD voltage. If the LVD is enabled in stop by setting the LVDE and the LVDSE bits in SPMSC1 when
the CPU executes a STOP instruction, then the voltage regulator remains active during stop mode. If the
user attempts to enter either stop1 or stop2 with the LVD enabled for stop (LVDSE = 1), the MCU will
instead enter stop3. The table below summarizes the behavior of the MCU in stop when the LVD is
enabled.
Table 3-3. LVD Enabled Stop Mode Behavior
CPU, Digital
ModePDCPPDC
Stop3Don’t
care
1
Either ATD stop mode or power-down mode depending on the state of ATDPU.
Don’t
care
Peripherals,
FLASH
StandbyStandbyStandbyDisabled
RAMICGATDRegulatorI/O PinsRTI
1
ActiveStates
Optionally on
held
3.6.6On-Chip Peripheral Modules in Stop Modes
When the MCU enters any stop mode, system clocks to the internal peripheral modules are stopped. Even
in the exception case (ENBDM = 1), where clocks to the background debug logic continue to operate,
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor37
Chapter 3 Modes of Operation
clocks to the peripheral systems are halted to reduce power consumption. Refer to Section 3.6.1, “Stop1
Mode,” Section 3.6.2, “Stop2 Mode,” and Section 3.6.3, “Stop3 Mode,” for specific information on system
behavior in stop modes.
I/O Pins
•All I/O pin states remain unchanged when the MCU enters stop3 mode.
•If the MCU is configured to go into stop2 mode, all I/O pins states are latched before entering stop.
•If the MCU is configured to go into stop1 mode, all I/O pins are forced to their default reset state
upon entry into stop.
Memory
•All RAM and register contents are preserved while the MCU is in stop3 mode.
•All registers will be reset upon wake-up from stop2, but the contents of RAM are preserved and
pin states remain latched until the PPDACK bit is written. The user may save any memory-mapped
register data into RAM before entering stop2 and restore the data upon exit from stop2.
•All registers will be reset upon wake-up from stop1 and the contents of RAM are not preserved.
The MCU must be initialized as upon reset. The contents of the FLASH memory are nonvolatile
and are preserved in any of the stop modes.
ICG — In stop3 mode, the ICG enters its low-power standby state. Either the oscillator or the internal
reference may be kept running when the ICG is in standby by setting the appropriate control bit. In both
stop2 and stop1 modes, the ICG is turned off. Neither the oscillator nor the internal reference can be kept
running in stop2 or stop1, even if enabled within the ICG module.
TPM — When the MCU enters stop mode, the clock to the TPM1 and TPM2 modules stop. The modules
halt operation. If the MCU is configured to go into stop2 or stop1 mode, the TPM modules will be reset
upon wake-up from stop and must be reinitialized.
ATD — When the MCU enters stop mode, the ATD will enter a low-power standby state
. No conversion
operation will occur while in stop. If the MCU is configured to go into stop2 or stop1 mode, the ATD will
be reset upon wake-up from stop and must be reinitialized.
KBI — During stop3, the KBI pins that are enabled continue to function as interrupt sources that are
capable of waking the MCU from stop3. The KBI is disabled in stop1 and stop2 and must be reinitialized
after waking up from either of these modes.
SCI — When the MCU enters stop mode, the clocks to the SCI1 and SCI2 modules stop. The modules
halt operation. If the MCU is configured to go into stop2 or stop1 mode, the SCI modules will be reset
upon wake-up from stop and must be reinitialized.
SPI — When the MCU enters stop mode, the clocks to the SPI module stop. The module halts operation.
If the MCU is configured to go into stop2 or stop1 mode, the SPI module will be reset upon wake-up from
stop and must be reinitialized.
IIC — When the MCU enters stop mode, the clocks to the IIC module stops. The module halts operation.
If the MCU is configured to go into stop2 or stop1 mode, the IIC module will be reset upon wake-up from
stop and must be reinitialized.
Voltage Regulator — The voltage regulator enters a low-power standby state when the MCU enters any
of the stop modes unless the LVD is enabled in stop mode or BDM is enabled.
MC9S08GB60A Data Sheet, Rev. 1.00
38Freescale Semiconductor
Chapter 4
Memory
4.1MC9S08GBxxA/GTxxA Memory Map
As shown in Figure 4-1, on-chip memory in the MC9S08GBxxA/GTxxA series of MCUs consists of
RAM, FLASH program memory for nonvolatile data storage, plus I/O and control/status registers. The
registers are divided into three groups:
•Direct-page registers (0x0000 through 0x007F)
•High-page registers (0x1800 through 0x182B)
•Nonvolatile registers (0xFFB0 through 0xFFBF)
DIRECT PAGE REGISTERS
RAM
4096 BYTES
0x0000
0x007F
0x0080
DIRECT PAGE REGISTERS
RAM
2048 BYTES
0x0000
0x007F
0x0080
0x087F
0x0880
0x107F
0x1080
FLASH
1920 BYTES
0x17FF
0x1800
HIGH PAGE REGISTERS
0x182B
0x182C
FLASH
59348 BYTES
0xFFFF
MC9S08GB60A/MC9S08GT60AMC9S08GB32A/MC9S08GT32A
UNIMPLEMENTED
3968 BYTES
HIGH PAGE REGISTERS
UNIMPLEMENTED
26580 BYTES
FLASH
32768 BYTES
Figure 4-1. MC9S08GBxxA/GTxxA Memory Map
0x17FF
0x1800
0x182B
0x182C
0x7FFF
0x8000
0xFFFF
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor39
Chapter 4 Memory
4.1.1Reset and Interrupt Vector Assignments
Table 4-1 shows address assignments for reset and interrupt vectors. The vector names shown in this table
are the labels used in the Freescale-provided equate file for the MC9S08GBxxA/GTxxA. For more details
about resets, interrupts, interrupt priority, and local interrupt mask controls, refer to Chapter 5, “Resets,
Interrupts, and System Configuration.”
Table 4-1. Reset and Interrupt Vectors
Address
(High/Low)
0xFFC0:FFC1
Unused Vector Space
(available for user program)
0xFFCA:FFCB
0xFFCC:FFCDRTIVrti
0xFFCE:FFCFIICViic1
0xFFD0:FFD1ATD ConversionVatd1
0xFFD2:FFD3KeyboardVkeyboard1
0xFFD4:FFD5SCI2 TransmitVsci2tx
0xFFD6:FFD7SCI2 ReceiveVsci2rx
0xFFD8:FFD9SCI2 ErrorVsci2err
0xFFDA:FFDBSCI1 TransmitVsci1tx
0xFFDC:FFDDSCI1 ReceiveVsci1rx
0xFFDE:FFDFSCI1 ErrorVsci1err
0xFFE0:FFE1SPIVspi1
0xFFE2:FFE3TPM2 OverflowVtpm2ovf
0xFFE4:FFE5TPM2 Channel 4Vtpm2ch4
0xFFE6:FFE7TPM2 Channel 3Vtpm2ch3
0xFFE8:FFE9TPM2 Channel 2Vtpm2ch2
0xFFEA:FFEBTPM2 Channel 1Vtpm2ch1
0xFFEC:FFEDTPM2 Channel 0Vtpm2ch0
0xFFEE:FFEFTPM1 OverflowVtpm1ovf
0xFFF0:FFF1TPM1 Channel 2Vtpm1ch2
0xFFF2:FFF3TPM1 Channel 1Vtpm1ch1
0xFFF4:FFF5TPM1 Channel 0Vtpm1ch0
0xFFF6:FFF7ICGVicg
0xFFF8:FFF9Low Voltage DetectVlvd
0xFFFA:FFFBIRQVirq
0xFFFC:FFFDSWIVswi
0xFFFE:FFFFResetVreset
VectorVector Name
MC9S08GB60A Data Sheet, Rev. 1.00
40Freescale Semiconductor
Chapter 4 Memory
4.2Register Addresses and Bit Assignments
The registers in the MC9S08GBxxA/GTxxA are divided into these three groups:
•Direct-page registers are located in the first 128 locations in the memory map, so they are
accessible with efficient direct addressing mode instructions.
•High-page registers are used much less often, so they are located above 0x1800 in the memory
map. This leaves more room in the direct page for more frequently used registers and variables.
•The nonvolatile register area consists of a block of 16 locations in FLASH memory at
0xFFB0–0xFFBF.
Nonvolatile register locations include:
— Three values which are loaded into working registers at reset
— An 8-byte backdoor comparison key which optionally allows a user to gain controlled access
to secure memory
Because the nonvolatile register locations are FLASH memory, they must be erased and
programmed like other FLASH memory locations.
Direct-page registers can be accessed with efficient direct addressing mode instructions. Bit manipulation
instructions can be used to access any bit in any direct-page register. Table 4-2 is a summary of all
user-accessible direct-page registers and control bits.
The direct page registers in Table 4-2 can use the more efficient direct addressing mode which only
requires the lower byte of the address. Because of this, the lower byte of the address in column one is
shown in bold text. In Table 4-3 and Table 4-4 the whole address in column one is shown in bold. In
Table 4-2, Table 4-3, and Table 4-4, the register names in column two are shown in bold to set them apart
from the bit names to the right. Cells that are not associated with named bits are shaded. A shaded cell with
a 0 indicates this unused bit always reads as a 0. Shaded cells with dashes indicate unused or reserved bit
locations that could read as 1s or 0s.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor41
Chapter 4 Memory
Table 4-2. Direct-Page Register Summary (Sheet 1 of 3)
AddressRegister NameBit 7654321Bit 0
0x0000PTAD
0x0001PTAPE
0x0002PTASE
0x0003PTADD
0x0004PTBD
0x0005PTBPE
0x0006PTBSE
0x0007PTBDD
0x0008PTCD
0x0009PTCPE
0x000APTCSE
0x000BPTCDD
0x000CPTDD
0x000DPTDPE
0x000EPTDSE
0x000FPTDDD
0x0010PTED
0x0011PTEPE
0x0012PTESE
0x0013PTEDD
0x0014IRQSC
0x0015Reserved
0x0016KBI1SC
0x0017KBI1PE
0x0018SCI1BDH
0x0019SCI1BDL
0x001ASCI1C1
0x001BSCI1C2
0x001CSCI1S1
0x001DSCI1S2
0x001ESCI1C3
0x001FSCI1D
0x0020SCI2BDH
0x0021SCI2BDL
0x0022SCI2C1
0x0023SCI2C2
0x0024SCI2S1
0x0025SCI2S2
0x0026SCI2C3
0x0027SCI2D
PTAD7PTAD6PTAD5PTAD4PTAD3PTAD2PTAD1PTAD0
PTAPE7PTAPE6PTAPE5PTAPE4PTAPE3PTAPE2PTAPE1PTAPE0
PTASE7PTASE6PTASE5PTASE4PTASE3PTASE2PTASE1PTASE0
PTADD7PTADD6PTADD5PTADD4PTADD3PTADD2PTADD1PTADD0
PTBD7PTBD6PTBD5PTBD4PTBD3PTBD2PTBD1PTBD0
PTBPE7PTBPE6PTBPE5PTBPE4PTBPE3PTBPE2PTBPE1PTBPE0
PTBSE7PTBSE6PTBSE5PTBSE4PTBSE3PTBSE2PTBSE1PTBSE0
PTBDD7PTBDD6PTBDD5PTBDD4PTBDD3PTBDD2PTBDD1PTBDD0
PTCD7PTCD6PTCD5PTCD4PTCD3PTCD2PTCD1PTCD0
PTCPE7PTCPE6PTCPE5PTCPE4PTCPE3PTCPE2PTCPE1PTCPE0
PTCSE7PTCSE6PTCSE5PTCSE4PTCSE3PTCSE2PTCSE1PTCSE0
PTCDD7PTCDD6PTCDD5PTCDD4PTCDD3PTCDD2PTCDD1PTCDD0
PTDD7PTDD6PTDD5PTDD4PTDD3PTDD2PTDD1PTDD0
PTDPE7PTDPE6PTDPE5PTDPE4PTDPE3PTDPE2PTDPE1PTDPE0
PTDSE7PTDSE6PTDSE5PTDSE4PTDSE3PTDSE2PTDSE1PTDSE0
PTDDD7PTDDD6PTDDD5PTDDD4PTDDD3PTDDD2PTDDD1PTDDD0
PTED7PTED6PTED5PTED4PTED3PTED2PTED1PTED0
PTEPE7PTEPE6PTEPE5PTEPE4PTEPE3PTEPE2PTEPE1PTEPE0
PTESE7PTESE6PTESE5PTESE4PTESE3PTESE2PTESE1PTESE0
PTEDD7PTEDD6PTEDD5PTEDD4PTEDD3PTEDD2PTEDD1PTEDD0
00IRQEDGIRQPEIRQFIRQACKIRQIEIRQMOD
————————
KBEDG7KBEDG6KBEDG5KBEDG4KBFKBACKKBIEKBIMOD
KBIPE7KBIPE6KBIPE5KBIPE4KBIPE3KBIPE2KBIPE1KBIPE0
000SBR12SBR11SBR10SBR9SBR8
SBR7SBR6SBR5SBR4SBR3SBR2SBR1SBR0
LOOPSSCISWAIRSRCMWAKEILTPEPT
TIETCIERIEILIETERERWUSBK
TDRETCRDRFIDLEORNFFEPF
0000000RAF
R8T8TXDIR0ORIENEIEFEIEPEIE
Bit 7654321Bit 0
000SBR12SBR11SBR10SBR9SBR8
SBR7SBR6SBR5SBR4SBR3SBR2SBR1SBR0
LOOPSSCISWAIRSRCMWAKEILTPEPT
TIETCIERIEILIETERERWUSBK
TDRETCRDRFIDLEORNFFEPF
0000000RAF
R8T8TXDIR0ORIENEIEFEIEPEIE
Bit 7654321Bit 0
MC9S08GB60A Data Sheet, Rev. 1.00
42Freescale Semiconductor
Chapter 4 Memory
Table 4-2. Direct-Page Register Summary (Sheet 2 of 3)
AddressRegister NameBit 7654321Bit 0
0x0028SPI1C1
0x0029SPI1C2
0x002ASPI1BR
0x002BSPI1S
0x002CReserved
0x002DSPI1D
0x002EReserved
0x002FReserved
0x0030TPM1SC
0x0031TPM1CNTH
0x0032TPM1CNTL
0x0033TPM1MODH
0x0034TPM1MODL
0x0035TPM1C0SC
0x0036TPM1C0VH
0x0037TPM1C0VL
0x0038TPM1C1SC
0x0039TPM1C1VH
0x003ATPM1C1VL
0x003BTPM1C2SC
0x003CTPM1C2VH
0x003DTPM1C2VL
0x003E–
0x003F
Reserved
0x0040PTFD
0x0041PTFPE
0x0042PTFSE
0x0043PTFDD
0x0044PTGD
0x0045PTGPE
0x0046PTGSE
0x0047PTGDD
0x0048ICGC1
0x0049ICGC2
0x004AICGS1
0x004BICGS2
0x004CICGFLTU
0x004DICGFLTL
0x004EICGTRM
0x004FReserved
SPIESPESPTIEMSTRCPOLCPHASSOELSBFE
000MODFENBIDIROE0SPISWAISPC0
0SPPR2SPPR1SPPR00SPR2SPR1SPR0
SPRF0SPTEFMODF0000
00000000
Bit 7654321Bit 0
00000000
00000000
TOFTOIECPWMSCLKSBCLKSAPS2PS1PS0
Bit 1514131211109Bit 8
Bit 7654321Bit 0
Bit 1514131211109Bit 8
Bit 7654321Bit 0
CH0FCH0IEMS0BMS0AELS0BELS0A00
Bit 1514131211109Bit 8
Bit 7654321Bit 0
CH1FCH1IEMS1BMS1AELS1BELS1A00
Bit 1514131211109Bit 8
Bit 7654321Bit 0
CH2FCH2IEMS2BMS2AELS2BELS2A00
Bit 1514131211109Bit 8
Bit 7654321Bit 0
—
—
PTFD7PTFD6PTFD5PTFD4PTFD3PTFD2PTFD1PTFD0
PTFPE7PTFPE6PTFPE5PTFPE4PTFPE3PTFPE2PTFPE1PTFPE0
PTFSE7PTFSE6PTFSE5PTFSE4PTFSE3PTFSE2PTFSE1PTFSE0
PTFDD7PTFDD6PTFDD5PTFDD4PTFDD3PTFDD2PTFDD1PTFDD0
PTGD7PTGD6PTGD5PTGD4PTGD3PTGD2PTGD1PTGD0
PTGPE7PTGPE6PTGPE5PTGPE4PTGPE3PTGPE2PTGPE1PTGPE0
PTGSE7PTGSE6PTGSE5PTGSE4PTGSE3PTGSE2PTGSE1PTGSE0
PTGDD7PTGDD6PTGDD5PTGDD4PTGDD3PTGDD2PTGDD1PTGDD0
HGORANGEREFSCLKSOSCSTENLOCD0
LOLREMFDLOCRERFD
CLKSTREFSTLOLSLOCKLOCSERCSICGIF
0000000DCOS
0000FLT
00000000
—
—
—
—
—
—
FLT
TRIM
—
—
—
—
—
—
—
—
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor43
Chapter 4 Memory
Table 4-2. Direct-Page Register Summary (Sheet 3 of 3)
AddressRegister NameBit 7654321Bit 0
0x0050ATD1C
0x0051ATD1SC
0x0052ATD1RH
0x0053ATD1RL
0x0054ATD1PE
0x0055–
0x0057
Reserved
0x0058IIC1A
0x0059IIC1F
0x005AIIC1C
0x005BIIC1S
0x005CIIC1D
0x005D–
0x005F
Reserved
0x0060TPM2SC
0x0061TPM2CNTH
0x0062TPM2CNTL
0x0063TPM2MODH
0x0064TPM2MODL
0x0065TPM2C0SC
0x0066TPM2C0VH
0x0067TPM2C0VL
0x0068TPM2C1SC
0x0069TPM2C1VH
0x006ATPM2C1VL
0x006BTPM2C2SC
0x006CTPM2C2VH
0x006DTPM2C2VL
0x006ETPM2C3SC
0x006FTPM2C3VH
0x0070TPM2C3VL
0x0071TPM2C4SC
0x0072TPM2C4VH
0x0073TPM2C4VL
0x0074–
0x007F
Reserved
ATDPUDJMRES8SGNPRS
CCFATDIEATDCOATDCH
Bit 7654321Bit 0
Bit 7654321Bit 0
ATDPE7ATDPE6ATDPE5ATDPE4ATDPE3ATDPE2ATDPE1ATDPE0
—
—
MULTICR
IICENIICIEMSTTXTXAKRSTA00
TCFIAASBUSYARBL0SRWIICIFRXAK
—
—
TOFTOIECPWMSCLKSBCLKSAPS2PS1PS0
Bit 1514131211109Bit 8
Bit 7654321Bit 0
Bit 1514131211109Bit 8
Bit 7654321Bit 0
CH0FCH0IEMS0BMS0AELS0BELS0A00
Bit 1514131211109Bit 8
Bit 7654321Bit 0
CH1FCH1IEMS1BMS1AELS1BELS1A00
Bit 1514131211109Bit 8
Bit 7654321Bit 0
CH2FCH2IEMS2BMS2AELS2BELS2A00
Bit 1514131211109Bit 8
Bit 7654321Bit 0
CH3FCH3IEMS3BMS3AELS3BELS3A00
Bit 1514131211109Bit 8
Bit 7654321Bit 0
CH4FCH4IEMS4BMS4AELS4BELS4A00
Bit 1514131211109Bit 8
Bit 7654321Bit 0
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
ADDR0
DATA
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
MC9S08GB60A Data Sheet, Rev. 1.00
44Freescale Semiconductor
Chapter 4 Memory
High-page registers, shown in Table 4-3, are accessed much less often than other I/O and control registers
so they have been located outside the direct addressable memory space, starting at 0x1800.
Table 4-3. High-Page Register Summary
AddressRegister NameBit 7654321Bit 0
0x1800SRS
0x1801SBDFR
0x1802SOPT
0x1803 –
0x1805
Reserved
0x1806SDIDH
0x1807SDIDL
0x1808SRTISC
0x1809SPMSC1
0x180ASPMSC2
0x180B–
0x180F
Reserved
0x1810DBGCAH
0x1811DBGCAL
0x1812DBGCBH
0x1813DBGCBL
0x1814DBGFH
0x1815DBGFL
0x1816DBGC
0x1817DBGT
0x1818DBGS
0x1819–
0x181F
Reserved
0x1820FCDIV
0x1821FOPT
0x1822Reserved
0x1823FCNFG
0x1824FPROT
0x1825FSTAT
0x1826FCMD
0x1827–
0x182B
Reserved
PORPINCOPILOP0ICGLVD0
0000000BDFR
COPECOPTSTOPE—00BKGDPE—
—
—
REV3REV2REV1REV0ID11ID10ID9ID8
ID7ID6ID5ID4ID3ID2ID1ID0
RTIFRTIACKRTICLKSRTIE0RTIS2RTIS1RTIS0
LVDFLVDACKLVDIELVDRELVDSELVDE00
LVWFLVWACKLVDVLVWVPPDFPPDACKPDCPPDC
—
—
Bit 1514131211109Bit 8
Bit 7654321Bit 0
Bit 1514131211109Bit 8
Bit 7654321Bit 0
Bit 1514131211109Bit 8
Bit 7654321Bit 0
DBGENARMTAGBRKENRWARWAENRWBRWBEN
TRGSELBEGIN00TRG3TRG2TRG1TRG0
AFBFARMF0CNT3CNT2CNT1CNT0
—
—
DIVLDPRDIV8DIV5DIV4DIV3DIV2DIV1DIV0
KEYENFNORED0000SEC01SEC00
————————
00KEYACC00000
FPOPENFPDISFPS2FPS1FPS0000
FCBEFFCCFFPVIOLFACCERR0FBLANK00
FCMD7FCMD6FCMD5FCMD4FCMD3FCMD2FCMD1FCMD0
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Nonvolatile FLASH registers, shown in Table 4-4, are located in the FLASH memory. These registers
include an 8-byte backdoor key which optionally can be used to gain access to secure memory resources.
During reset events, the contents of NVPROT and NVOPT in the nonvolatile register area of the FLASH
memory are transferred into corresponding FPROT and FOPT working registers in the high-page registers
to control security and block protection options.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor45
Chapter 4 Memory
Table 4-4. Nonvolatile Register Summary
AddressRegister NameBit 7654321Bit 0
0xFFB0 –
0xFFB7
0xFFB8 –
0xFFBC
0xFFBDNVPROT
0xFFBEReserved
0xFFBFNVOPT
1
This location is used to store the factory trim value for the ICG.
NVBACKKEY
Reserved
1
8-Byte Comparison Key
—
—
FPOPENFPDISFPS2FPS1FPS0000
————————
KEYENFNORED0000SEC01SEC00
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Provided the key enable (KEYEN) bit is 1, the 8-byte comparison key can be used to temporarily
disengage memory security. This key mechanism can be accessed only through user code running in secure
memory. (A security key cannot be entered directly through background debug commands.) This security
key can be disabled completely by programming the KEYEN bit to 0. If the security key is disabled, the
only way to disengage security is by mass erasing the FLASH if needed (normally through the background
debug interface) and verifying that FLASH is blank. To avoid returning to secure mode after the next reset,
program the security bits (SEC01:SEC00) to the unsecured state (1:0).
4.3RAM
The MC9S08GBxxA/GTxxA includes static RAM. The locations in RAM below 0x0100 can be accessed
using the more efficient direct addressing mode, and any single bit in this area can be accessed with the bit
manipulation instructions (BCLR, BSET, BRCLR, and BRSET). Locating the most frequently accessed
program variables in this area of RAM is preferred.
The RAM retains data when the MCU is in low-power wait, stop2, or stop3 mode. At power-on or after
wakeup from stop1, the contents of RAM are uninitialized. RAM data is unaffected by any reset provided
that the supply voltage does not drop below the minimum value for RAM retention.
For compatibility with older M68HC05 MCUs, the HCS08 resets the stack pointer to 0x00FF. In the
MC9S08GBxxA/GTxxA, it is usually best to re-initialize the stack pointer to the top of the RAM so the
direct page RAM can be used for frequently accessed RAM variables and bit-addressable program
variables. Include the following 2-instruction sequence in your reset initialization routine (where RamLast
is equated to the highest address of the RAM in the Freescale-provided equate file).
LDHX #RamLast+1 ;point one past RAM
TXS ;SP<-(H:X-1)
When security is enabled, the RAM is considered a secure memory resource and is not accessible through
BDM or through code executing from non-secure memory. See Section 4.5, “Security” for a detailed
description of the security feature.
4.4FLASH
The FLASH memory is intended primarily for program storage. In-circuit programming allows the
operating program to be loaded into the FLASH memory after final assembly of the application product.
MC9S08GB60A Data Sheet, Rev. 1.00
46Freescale Semiconductor
Chapter 4 Memory
It is possible to program the entire array through the single-wire background debug interface. Because no
special voltages are needed for FLASH erase and programming operations, in-application programming
is also possible through other software-controlled communication paths. For a more detailed discussion of
in-circuit and in-application programming, refer to the HCS08 Family Reference Manual, Volume I,
Freescale Semiconductor document order number HCS08RMv1/D.
•Command interface for fast program and erase operation
•Up to 100,000 program/erase cycles at typical voltage and temperature
•Flexible block protection
•Security feature for FLASH and RAM
•Auto power-down for low-frequency read accesses
4.4.2Program and Erase Times
Before any program or erase command can be accepted, the FLASH clock divider register (FCDIV) must
be written to set the internal clock for the FLASH module to a frequency (f
200 kHz (see Table 4.6.1). This register can be written only once, so normally this write is done during
reset initialization. FCDIV cannot be written if the access error flag, FACCERR in FSTAT, is set. The user
must ensure that FACCERR is not set before writing to the FCDIV register. One period of the resulting
clock (1/f
) is used by the command processor to time program and erase pulses. An integer number
FCLK
of these timing pulses is used by the command processor to complete a program or erase command.
Table 4-5 shows program and erase times. The bus clock frequency and FCDIV determine the frequency
of FCLK (f
). The time for one cycle of FCLK is t
FCLK
of cycles of FCLK and as an absolute time for the case where t
FCLK
= 1/f
FCLK
. The times are shown as a number
FCLK
=5µs. Program and erase times
shown include overhead for the command state machine and enabling and disabling of program and erase
voltages.
Table 4-5. Program and Erase Times
ParameterCycles of FCLKTime if FCLK = 200 kHz
Byte program945 µs
Byte program (burst)4
Page erase400020 ms
Mass erase20,000100 ms
1
Excluding start/end overhead
) between 150 kHz and
FCLK
1
20 µs
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor47
Chapter 4 Memory
4.4.3Program and Erase Command Execution
The steps for executing any of the commands are listed below. The FCDIV register must be initialized and
any error flags cleared before beginning command execution. The command execution steps are:
1. Write a data value to an address in the FLASH array. The address and data information from this
write is latched into the FLASH interface. This write is a required first step in any command
sequence. For erase and blank check commands, the value of the data is not important. For page
erase commands, the address may be any address in the 512-byte page of FLASH to be erased. For
mass erase and blank check commands, the address can be any address in the FLASH memory.
Whole pages of 512 bytes are the smallest blocks of FLASH that may be erased. In the 60K
version, there are two instances where the size of a block that is accessible to the user is less than
512 bytes: the first page following RAM, and the first page following the high page registers. These
pages are overlapped by the RAM and high page registers, respectively.
NOTE
Do not program any byte in the FLASH more than once after a successful
erase operation. Reprogramming bits in a byte which is already
programmed is not allowed without first erasing the page in which the byte
resides or mass erasing the entire FLASH memory. Programming without
first erasing may disturb data stored in the FLASH.
2. Write the command code for the desired command to FCMD. The five valid commands are blank
check (0x05), byte program (0x20), burst program (0x25), page erase (0x40), and mass erase
(0x41). The command code is latched into the command buffer.
3. Write a 1 to the FCBEF bit in FSTAT to clear FCBEF and launch the command (including its
address and data information).
A partial command sequence can be aborted manually by writing a 0 to FCBEF any time after the write to
the memory array and before writing the 1 that clears FCBEF and launches the complete command.
Aborting a command in this way sets the FACCERR access error flag which must be cleared before
starting a new command.
A strictly monitored procedure must be adhered to, or the command will not be accepted. This minimizes
the possibility of any unintended change to the FLASH memory contents. The command complete flag
(FCCF) indicates when a command is complete. The command sequence must be completed by clearing
FCBEF to launch the command. Figure 4-2 is a flowchart for executing all of the commands except for
burst programming. The FCDIV register must be initialized before using any FLASH commands. This
must be done only once following a reset.
MC9S08GB60A Data Sheet, Rev. 1.00
48Freescale Semiconductor
START
Chapter 4 Memory
FACCERR ?
CLEAR ERROR
WRITE TO FCDIV
WRITE TO FLASH
TO BUFFER ADDRESS AND DATA
WRITE COMMAND TO FCMD
WRITE 1 TO FCBEF
TO LAUNCH COMMAND
AND CLEAR FCBEF
FPVIO OR
FACCERR ?
NO
0
FCCF ?
1
DONE
0
(1)
(2)
YES
(1)
Only required once
after reset.
(2)
Wait at least four bus cycles before
checking FCBEF or FCCF.
ERROR EXIT
Figure 4-2. FLASH Program and Erase Flowchart
4.4.4Burst Program Execution
The burst program command is used to program sequential bytes of data in less time than would be
required using the standard program command. This is possible because the high voltage to the FLASH
array does not need to be disabled between program operations. Ordinarily, when a program or erase
command is issued, an internal charge pump associated with the FLASH memory must be enabled to
supply high voltage to the array. Upon completion of the command, the charge pump is turned off. When
a burst program command is issued, the charge pump is enabled and then remains enabled after completion
of the burst program operation if the following two conditions are met:
1. The next burst program command has been queued before the current program operation has
completed.
2. The next sequential address selects a byte on the same physical row as the current byte being
programmed. A row of FLASH memory consists of 64 bytes. A byte within a row is selected by
addresses A5 through A0. A new row begins when addresses A5 through A0 are all zero.
The first byte of a series of sequential bytes being programmed in burst mode will take the same amount
of time to program as a byte programmed in standard mode. Subsequent bytes will program in the burst
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor49
Chapter 4 Memory
program time provided that the conditions above are met. In the case the next sequential address is the
beginning of a new row, the program time for that byte will be the standard time instead of the burst time.
This is because the high voltage to the array must be disabled and then enabled again. If a new burst
command has not been queued before the current command completes, then the charge pump will be
disabled and high voltage removed from the array.
START
FACCERR ?
CLEAR ERROR
WRITE TO FCDIV
FCBEF ?
WRITE TO FLASH
TO BUFFER ADDRESS AND DATA
WRITE COMMAND TO FCMD
WRITE 1 TO FCBEF
TO LAUNCH COMMAND
AND CLEAR FCBEF
FPVIO OR
FACCERR ?
YES
NEW BURST COMMAND ?
NO
NO
0
1
(1)
1
(2)
(1)
Only required once
after reset.
0
(2)
Wait at least four bus cycles before
checking FCBEF or FCCF.
YES
ERROR EXIT
0
FCCF ?
1
DONE
Figure 4-3. FLASH Burst Program Flowchart
MC9S08GB60A Data Sheet, Rev. 1.00
50Freescale Semiconductor
Chapter 4 Memory
4.4.5Access Errors
An access error occurs whenever the command execution protocol is violated.
Any of the following specific actions will cause the access error flag (FACCERR) in FSTAT to be set.
FACCERR must be cleared by writing a 1 to FACCERR in FSTAT before any command can be processed.
•Writing to a FLASH address before the internal FLASH clock frequency has been set by writing
to the FCDIV register
•Writing to a FLASH address while FCBEF is not set (A new command cannot be started until the
command buffer is empty.)
•Writing a second time to a FLASH address before launching the previous command (There is only
one write to FLASH for every command.)
•Writing a second time to FCMD before launching the previous command (There is only one write
to FCMD for every command.)
•Writing to any FLASH control register other than FCMD after writing to a FLASH address
•Writing any command code other than the five allowed codes (0x05, 0x20, 0x25, 0x40, or 0x41)
to FCMD
•Accessing (read or write) any FLASH control register other than the write to FSTAT (to clear
FCBEF and launch the command) after writing the command to FCMD
•The MCU enters stop mode while a program or erase command is in progress (The command is
aborted.)
•Writing the byte program, burst program, or page erase command code (0x20, 0x25, or 0x40) with
a background debug command while the MCU is secured (The background debug controller can
only do blank check and mass erase commands when the MCU is secure.)
•Writing 0 to FCBEF to cancel a partial command
4.4.6FLASH Block Protection
Block protection prevents program or erase changes for FLASH memory locations in a designated address
range. Mass erase is disabled when any block of FLASH is protected. The MC9S08GBxxA/GTxxA allows
a block of memory at the end of FLASH, and/or the entire FLASH memory to be block protected. A
disable control bit and a 3-bit control field, allows the user to set the size of this block. A separate control
bit allows block protection of the entire FLASH memory array. All seven of these control bits are located
in the FPROT register (see Section 4.6.4, “FLASH Protection Register (FPROT and NVPROT)”).
At reset, the high-page register (FPROT) is loaded with the contents of the NVPROT location which is in
the nonvolatile register block of the FLASH memory. The value in FPROT cannot be changed directly
from application software so a runaway program cannot alter the block protection settings. If the last 512
bytes of FLASH which includes the NVPROT register is protected, the application program cannot alter
the block protection settings (intentionally or unintentionally). The FPROT control bits can be written by
background debug commands to allow a way to erase a protected FLASH memory.
One use for block protection is to block protect an area of FLASH memory for a bootloader program. This
bootloader program then can be used to erase the rest of the FLASH memory and reprogram it. Because
the bootloader is protected, it remains intact even if MCU power is lost in the middle of an erase and
reprogram operation.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor51
Chapter 4 Memory
4.4.7Vector Redirection
Whenever any block protection is enabled, the reset and interrupt vectors will be protected. Vector
redirection allows users to modify interrupt vector information without unprotecting bootloader and reset
vector space. Vector redirection is enabled by programming the FNORED bit in the NVOPT register
located at address 0xFFBF to zero. For redirection to occur, at least some portion but not all of the FLASH
memory must be block protected by programming the NVPROT register located at address 0xFFBD. All
of the interrupt vectors (memory locations 0xFFC0–0xFFFD) are redirected, while the reset vector
(0xFFFE:FFFF) is not. When more than 32K is protected, vector redirection must not be enabled.
For example, if 512 bytes of FLASH are protected, the protected address region is from 0xFE00 through
0xFFFF. The interrupt vectors (0xFFC0–0xFFFD) are redirected to the locations 0xFDC0–0xFDFD. Now,
if an SPI interrupt is taken for instance, the values in the locations 0xFDE0:FDE1 are used for the vector
instead of the values in the locations 0xFFE0:FFE1. This allows the user to reprogram the unprotected
portion of the FLASH with new program code including new interrupt vector values while leaving the
protected area, which includes the default vector locations, unchanged.
4.5Security
The MC9S08GBxxA/GTxxA includes circuitry to prevent unauthorized access to the contents of FLASH
and RAM memory. When security is engaged, FLASH and RAM are considered secure resources.
Direct-page registers, high-page registers, and the background debug controller are considered unsecured
resources. Programs executing within secure memory have normal access to any MCU memory locations
and resources. Attempts to access a secure memory location with a program executing from an unsecured
memory space or through the background debug interface are blocked (writes are ignored and reads return
all 0s).
Security is engaged or disengaged based on the state of two nonvolatile register bits (SEC01:SEC00) in
the FOPT register. During reset, the contents of the nonvolatile location NVOPT are copied from FLASH
into the working FOPT register in high-page register space. A user engages security by programming the
NVOPT location which can be done at the same time the FLASH memory is programmed. The 1:0 state
disengages security while the other three combinations engage security. Notice the erased state (1:1)
makes the MCU secure. During development, whenever the FLASH is erased, it is good practice to
immediately program the SEC00 bit to 0 in NVOPT so SEC01:SEC00 = 1:0. This would allow the MCU
to remain unsecured after a subsequent reset.
The on-chip debug module cannot be enabled while the MCU is secure. The separate background debug
controller can still be used for background memory access commands, but the MCU cannot enter active
background mode except by holding BKGD/MS low at the rising edge of reset.
A user can choose to allow or disallow a security unlocking mechanism through an 8-byte backdoor
security key. If the nonvolatile KEYEN bit in NVOPT/FOPT is 0, the backdoor key is disabled and there
is no way to disengage security without completely erasing all FLASH locations. If KEYEN is 1, a secure
user program can temporarily disengage security by:
1. Writing 1 to KEYACC in the FCNFG register. This makes the FLASH module interpret writes to
the backdoor comparison key locations (NVBACKKEY through NVBACKKEY+7) as values to
be compared against the key rather than as the first step in a FLASH program or erase command.
MC9S08GB60A Data Sheet, Rev. 1.00
52Freescale Semiconductor
Chapter 4 Memory
2. Writing the user-entered key values to the NVBACKKEY through NVBACKKEY+7 locations.
These writes must be done in order, starting with the value for NVBACKKEY and ending with
NVBACKKEY+7. STHX should not be used for these writes because these writes cannot be done
on adjacent bus cycles. User software normally would get the key codes from outside the MCU
system through a communication interface such as a serial I/O.
3. Writing 0 to KEYACC in the FCNFG register. If the 8-byte key that was just written matches the
key stored in the FLASH locations, SEC01:SEC00 are automatically changed to 1:0 and security
will be disengaged until the next reset.
The security key can be written only from RAM, so it cannot be entered through background commands
without the cooperation of a secure user program. The FLASH memory cannot be accessed by read
operations while KEYACC is set.
The backdoor comparison key (NVBACKKEY through NVBACKKEY+7) is located in FLASH memory
locations in the nonvolatile register space so users can program these locations just as they would program
any other FLASH memory location. The nonvolatile registers are in the same 512-byte block of FLASH
as the reset and interrupt vectors, so block protecting that space also block protects the backdoor
comparison key. Block protects cannot be changed from user application programs, so if the vector space
is block protected, the backdoor security key mechanism cannot permanently change the block protect,
security settings, or the backdoor key.
Security can always be disengaged through the background debug interface by performing these steps:
1. Disable any block protections by writing FPROT. FPROT can be written only with background
debug commands, not from application software.
2. Mass erase FLASH, if necessary.
3. Blank check FLASH. Provided FLASH is completely erased, security is disengaged until the next
reset.
To avoid returning to secure mode after the next reset, program NVOPT so SEC01:SEC00 = 1:0.
4.6FLASH Registers and Control Bits
The FLASH module has nine 8-bit registers in the high-page register space, three locations in the
nonvolatile register space in FLASH memory that are copied into three corresponding high-page control
registers at reset. There is also an 8-byte comparison key in FLASH memory. Refer to Table 4-3 and
Table 4-4 for the absolute address assignments for all FLASH registers. This section refers to registers and
control bits only by their names. A Freescale-provided equate or header file normally is used to translate
these names into the appropriate absolute addresses.
4.6.1FLASH Clock Divider Register (FCDIV)
Bit 7 of this register is a read-only status flag. Bits 6 through 0 may be read at any time but can be written
only one time. Before any erase or programming operations are possible, write to this register to set the
frequency of the clock for the nonvolatile memory system within acceptable limits.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor53
Chapter 4 Memory
76543210
RDIVLD
PRDIV8DIV5DIV4DIV3DIV2DIV1DIV0
W
Reset00000000
= Unimplemented or Reserved
Figure 4-4. FLASH Clock Divider Register (FCDIV)
Table 4-6. FCDIV Field Descriptions
FieldDescription
7
DIVLD
6
PRDIV8
5
DIV[5:0]
Divisor Loaded Status Flag — When set, this read-only status flag indicates that the FCDIV register has been
written since reset. Reset clears this bit and the first write to this register causes this bit to become set regardless
of the data written.
0 FCDIV has not been written since reset; erase and program operations disabled for FLASH.
1 FCDIV has been written since reset; erase and program operations enabled for FLASH.
Prescale (Divide) FLASH Clock by 8
0 Clock input to the FLASH clock divider is the bus rate clock.
1 Clock input to the FLASH clock divider is the bus rate clock divided by 8.
Divisor for FLASH Clock Divider — The FLASH clock divider divides the bus rate clock (or the bus rate clock
divided by 8 if PRDIV8 = 1) by the value in the 6-bit DIV5:DIV0 field plus one. The resulting frequency of the
internal FLASH clock must fall within the range of 200 kHz to 150 kHz for proper FLASH operations.
Program/erase timing pulses are one cycle of this internal FLASH clock, which corresponds to a range of 5 µs
to 6.7 µs. The automated programming logic uses an integer number of these pulses to complete an erase or
program operation. See Equation 4-1 and Equation 4-2. Table 4-7 shows the appropriate values for PRDIV8 and
DIV5:DIV0 for selected bus frequencies.
if PRDIV8 = 0 — f
if PRDIV8 = 1 — f
FCLK
FCLK
= f
= f
Bus
÷ ([DIV5:DIV0] + 1)Eqn. 4-1
Bus
÷ (8 × ([DIV5:DIV0] + 1))Eqn. 4-2
Table 4-7. FLASH Clock Divider Settings
f
Bus
PRDIV8
(Binary)
DIV5:DIV0
(Decimal)
f
FCLK
Program/Erase Timing Pulse
(5 µs Min, 6.7 µs Max)
20 MHz112192.3 kHz5.2 µs
10 MHz049200 kHz5 µs
8 MHz039200 kHz5 µs
4 MHz019200 kHz5 µs
2 MHz09200 kHz5 µs
1 MHz04200 kHz5 µs
200 kHz00200 kHz5 µs
150 kHz00150 kHz6.7 µs
MC9S08GB60A Data Sheet, Rev. 1.00
54Freescale Semiconductor
Chapter 4 Memory
4.6.2FLASH Options Register (FOPT and NVOPT)
During reset, the contents of the nonvolatile location NVOPT are copied from FLASH into FOPT. Bits 5
through 2 are not used and always read 0. This register may be read at any time, but writes have no meaning
or effect. To change the value in this register, erase and reprogram the NVOPT location in FLASH memory
as usual and then issue a new MCU reset.
76543210
R
KEYENFNORED
W
ResetThis register is loaded from nonvolatile location NVOPT during reset.
= Unimplemented or Reserved
Figure 4-5. FLASH Options Register (FOPT)
FieldDescription
0000SEC01SEC00
Table 4-8. FOPT Field Descriptions
7
KEYEN
6
FNORED
1:0
SEC0[1:0]
Backdoor Key Mechanism Enable — When this bit is 0, the backdoor key mechanism cannot be used to
disengage security. The backdoor key mechanism is accessible only from user (secured) firmware. BDM
commands cannot be used to write key comparison values that would unlock the backdoor key. For more detailed
information about the backdoor key mechanism, refer to Section 4.5, “Security.”
0 No backdoor key access allowed.
1 If user firmware writes an 8-byte value that matches the nonvolatile backdoor key (NVBACKKEY through
NVBACKKEY+7, in that order), security is temporarily disengaged until the next MCU reset.
Vector Redirection Disable — When this bit is 1, vector redirection is disabled.
0 Vector redirection enabled.
1 Vector redirection disabled.
Security State Code — This 2-bit field determines the security state of the MCU as shown below. When the
MCU is secure, the contents of RAM and FLASH memory cannot be accessed by instructions from any
unsecured source including the background debug interface. For more detailed information about security, refer
to Section 4.5, “Security.”
00 Secure
01 Secure
10 Unsecured
11 Secure
SEC0[1:0] changes to 10 after successful backdoor key entry or a successful blank check of FLASH.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor55
Chapter 4 Memory
4.6.3FLASH Configuration Register (FCNFG)
Bits 7 through 5 may be read or written at any time. Bits 4 through 0 always read 0 and cannot be written.
76543210
R00
KEYACC
W
Reset00000000
= Unimplemented or Reserved
Figure 4-6. FLASH Configuration Register (FCNFG)
Table 4-9. FCNFG Field Descriptions
FieldDescription
00000
5
KEYACC
Enable Writing of Access Key — This bit enables writing of the backdoor comparison key. For more detailed
information about the backdoor key mechanism, refer to Section 4.5, “Security.”
0 Writes to 0xFFB0–0xFFB7 are interpreted as the start of a FLASH programming or erase command.
1 Writes to NVBACKKEY (0xFFB0–0xFFB7) are interpreted as comparison key writes.
Reads of the FLASH return invalid data.
4.6.4FLASH Protection Register (FPROT and NVPROT)
During reset, the contents of the nonvolatile location NVPROT is copied from FLASH into FPROT. Bits 0,
1, and 2 are not used and each always reads as 0. This register may be read at any time, but user program
writes have no meaning or effect. Background debug commands can write to FPROT.
76543210
RFPOPENFPDISFPS2FPS1FPS0000
W
ResetThis register is loaded from nonvolatile location NVPROT during reset.
1
Background commands can be used to change the contents of these bits in FPROT.
(1)
(1)(1)(1)(1)
= Unimplemented or Reserved
Figure 4-7. FLASH Protection Register (FPROT)
Table 4-10. FPROT Field Descriptions
FieldDescription
7
FPOPEN
56Freescale Semiconductor
Open Unprotected FLASH for Program/Erase
0 Entire FLASH memory is block protected (no program or erase allowed).
1 Any FLASH location, not otherwise block protected or secured, may be erased or programmed.
MC9S08GB60A Data Sheet, Rev. 1.00
Table 4-10. FPROT Field Descriptions (continued)
FieldDescription
Chapter 4 Memory
6
FPDIS
FLASH Protection Disable
0 FLASH block specified by FPS2:FPS0 is block protected (program and erase not allowed).
1 No FLASH block is protected.
5:3
FPS[2:0]
FLASH Protect Size Selects — When FPDIS = 0, this 3-bit field determines the size of a protected block of
FLASH locations at the high address end of the FLASH (see Table 4-11). Protected FLASH locations cannot be
erased or programmed.
Bits 3, 1, and 0 always read 0 and writes have no meaning or effect. The remaining five bits are status bits
that can be read at any time. Writes to these bits have special meanings that are discussed in the bit
descriptions.
76543210
R
FCBEF
W
Reset11000000
FieldDescription
FCCF
FPVIOLFACCERR
= Unimplemented or Reserved
Figure 4-8. FLASH Status Register (FSTAT)
Table 4-12. FSTAT Field Descriptions
0FBLANK00
7
FCBEF
6
FCCF
5
FPVIOL
4
FACCERR
2
FBLANK
FLASH Command Buffer Empty Flag — The FCBEF bit is used to launch commands. It also indicates that the
command buffer is empty so that a new command sequence can be executed when performing burst
programming. The FCBEF bit is cleared by writing a 1 to it or when a burst program command is transferred to
the array for programming. Only burst program commands can be buffered.
0 Command buffer is full (not ready for additional commands).
1 A new burst program command may be written to the command buffer.
FLASH Command Complete Flag — FCCF is set automatically when the command buffer is empty and no
command is being processed. FCCF is cleared automatically when a new command is started (by writing 1 to
FCBEF to register a command). Writing to FCCF has no meaning or effect.
0 Command in progress
1 All commands complete
Protection Violation Flag — FPVIOL is set automatically when FCBEF is cleared to register a command that
attempts to erase or program a location in a protected block (the erroneous command is ignored). FPVIOL is
cleared by writing a 1 to FPVIOL.
0 No protection violation.
1 An attempt was made to erase or program a protected location.
Access Error Flag — FACCERR is set automatically when the proper command sequence is not followed
exactly (the erroneous command is ignored), if a program or erase operation is attempted before the FCDIV
register has been initialized, or if the MCU enters stop while a command was in progress. For a more detailed
discussion of the exact actions that are considered access errors, see Section 4.4.5, “Access Errors.” FACCERR
is cleared by writing a 1 to FACCERR. Writing a 0 to FACCERR has no meaning or effect.
0 No access error has occurred.
1 An access error has occurred.
FLASH Verified as All Blank (Erased) Flag — FBLANK is set automatically at the conclusion of a blank check
command if the entire FLASH array was verified to be erased. FBLANK is cleared by clearing FCBEF to write a
new valid command. Writing to FBLANK has no meaning or effect.
0 After a blank check command is completed and FCCF = 1, FBLANK = 0 indicates the FLASH array is not
completely erased.
1 After a blank check command is completed and FCCF = 1, FBLANK = 1 indicates the FLASH array is
completely erased (all 0xFF).
MC9S08GB60A Data Sheet, Rev. 1.00
58Freescale Semiconductor
Chapter 4 Memory
4.6.6FLASH Command Register (FCMD)
Only five command codes are recognized in normal user modes as shown in Table 4-14. Refer to
Section 4.4.3, “Program and Erase Command Execution” for a detailed discussion of FLASH
programming and erase operations.
76543210
R00000000
WFCMD7FCMD6FCMD5FCMD4FCMD3FCMD2FCMD1FCMD0
Reset00000000
Figure 4-9. FLASH Command Register (FCMD)
Table 4-13. FCMD Field Descriptions
FieldDescription
7:0
FCMD[7:0]
See Table 4-14 for a description of FCMD[7:0].
Table 4-14. FLASH Commands
CommandFCMDEquate File Label
Blank check0x05mBlank
Byte program0x20mByteProg
Byte program — burst mode0x25mBurstProg
Page erase (512 bytes/page)0x40mPageErase
Mass erase (all FLASH)0x41mMassErase
All other command codes are illegal and generate an access error.
It is not necessary to perform a blank check command after a mass erase operation. Only blank check is
required as part of the security unlocking mechanism.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor59
Chapter 4 Memory
MC9S08GB60A Data Sheet, Rev. 1.00
60Freescale Semiconductor
Chapter 5
Resets, Interrupts, and System Configuration
5.1Introduction
This section discusses basic reset and interrupt mechanisms and the various sources of reset and interrupts
in the MC9S08GBxxA/GTxxA. Some interrupt sources from peripheral modules are discussed in greater
detail within other sections of this data manual. This section gathers basic information about all reset and
interrupt sources in one place for easy reference. A few reset and interrupt sources, including the computer
operating properly (COP) watchdog and real-time interrupt (RTI), are not part of on-chip peripheral
systems with their own sections but are part of the system control logic.
5.2Features
Reset and interrupt features include:
•Multiple sources of reset for flexible system configuration and reliable operation:
— Power-on detection (POR)
— Low voltage detection (LVD) with enable
— External
— COP watchdog with enable and two timeout choices
RESET pin with enable
— Illegal opcode
— Serial command from a background debug host
•Reset status register (SRS) to indicate source of most recent reset
•Separate interrupt vectors for each module (reduces polling overhead) (see Table 5-1)
5.3MCU Reset
Resetting the MCU provides a way to start processing from a known set of initial conditions. During reset,
most control and status registers are forced to initial values and the program counter is loaded from the
reset vector (0xFFFE:0xFFFF). On-chip peripheral modules are disabled and I/O pins are initially
configured as general-purpose high-impedance inputs with pullup devices disabled. The I bit in the
condition code register (CCR) is set to block maskable interrupts so the user program has a chance to
initialize the stack pointer (SP) and system control settings. SP is forced to 0x00FF at reset.
The MC9S08GBxxA/GTxxA has seven sources for reset:
•Power-on reset (POR)
•Low-voltage detect (LVD)
•Computer operating properly (COP) timer
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor61
Chapter 5 Resets, Interrupts, and System Configuration
•Illegal opcode detect
•Background debug forced reset
•The reset pin (
RESET)
•Clock generator loss of lock and loss of clock reset
Each of these sources, with the exception of the background debug forced reset, has an associated bit in
the system reset status register. Whenever the MCU enters reset, the internal clock generator (ICG) module
switches to self-clocked mode with the frequency of f
Self_reset
selected. The reset pin is driven low for 34
internal bus cycles where the internal bus frequency is half the ICG frequency. After the 34 cycles are
completed, the pin is released and will be pulled up by the internal pullup resistor, unless it is held low
externally. After the pin is released, it is sampled after another 38 cycles to determine whether the reset pin
is the cause of the MCU reset.
5.4Computer Operating Properly (COP) Watchdog
The COP watchdog is intended to force a system reset when the application software fails to execute as
expected. To prevent a system reset from the COP timer (when it is enabled), application software must
reset the COP timer periodically. If the application program gets lost and fails to reset the COP before it
times out, a system reset is generated to force the system back to a known starting point. The COP
watchdog is enabled by the COPE bit in SOPT (see Section 5.8.4, “System Options Register (SOPT)” for
additional information). The COP timer is reset by writing any value to the address of SRS. This write does
not affect the data in the read-only SRS. Instead, the act of writing to this address is decoded and sends a
reset signal to the COP timer.
After any reset, the COP timer is enabled. This provides a reliable way to detect code that is not executing
as intended. If the COP watchdog is not used in an application, it can be disabled by clearing the COPE
bit in the write-once SOPT register. Also, the COPT bit can be used to choose one of two timeout periods
18
or 213cycles of the bus rate clock). Even if the application will use the reset default settings in COPE
(2
and COPT, the user should still write to write-once SOPT during reset initialization to lock in the settings.
That way, they cannot be changed accidentally if the application program gets lost.
The write to SRS that services (clears) the COP timer should not be placed in an interrupt service routine
(ISR) because the ISR could continue to be executed periodically even if the main application program
fails.
When the MCU is in active background mode, the COP timer is temporarily disabled.
5.5Interrupts
Interrupts provide a way to save the current CPU status and registers, execute an interrupt service routine
(ISR), and then restore the CPU status so processing resumes where it left off before the interrupt. Other
than the software interrupt (SWI), which is a program instruction, interrupts are caused by hardware events
such as an edge on the IRQ pin or a timer-overflow event. The debug module can also generate an SWI
under certain circumstances.
If an event occurs in an enabled interrupt source, an associated read-only status flag will become set. The
CPU will not respond until and unless the local interrupt enable is set to 1 to enable the interrupt. The I bit
MC9S08GB60A Data Sheet, Rev. 1.00
62Freescale Semiconductor
Chapter 5 Resets, Interrupts, and System Configuration
in the CCR is 0 to allow interrupts. The global interrupt mask (I bit) in the CCR is initially set after reset
which masks (prevents) all maskable interrupt sources. The user program initializes the stack pointer and
performs other system setup before clearing the I bit to allow the CPU to respond to interrupts.
When the CPU receives a qualified interrupt request, it completes the current instruction before responding
to the interrupt. The interrupt sequence follows the same cycle-by-cycle sequence as the SWI instruction
and consists of:
•Saving the CPU registers on the stack
•Setting the I bit in the CCR to mask further interrupts
•Fetching the interrupt vector for the highest-priority interrupt that is currently pending
•Filling the instruction queue with the first three bytes of program information starting from the
address fetched from the interrupt vector locations
While the CPU is responding to the interrupt, the I bit is automatically set to avoid the possibility of another
interrupt interrupting the ISR itself (this is called nesting of interrupts). Normally, the I bit is restored to 0
when the CCR is restored from the value stacked on entry to the ISR. In rare cases, the I bit may be cleared
inside an ISR (after clearing the status flag that generated the interrupt) so that other interrupts can be
serviced without waiting for the first service routine to finish. This practice is not recommended for anyone
other than the most experienced programmers because it can lead to subtle program errors that are difficult
to debug.
The interrupt service routine ends with a return-from-interrupt (RTI) instruction which restores the CCR,
A, X, and PC registers to their pre-interrupt values by reading the previously saved information off the
stack.
NOTE
For compatibility with the M68HC08, the H register is not automatically
saved and restored. It is good programming practice to push H onto the stack
at the start of the interrupt service routine (ISR) and restore it just before the
RTI that is used to return from the ISR.
When two or more interrupts are pending when the I bit is cleared, the highest priority source is serviced
first (see Table 5-1).
5.5.1Interrupt Stack Frame
Figure 5-1 shows the contents and organization of a stack frame. Before the interrupt, the stack pointer
(SP) points at the next available byte location on the stack. The current values of CPU registers are stored
on the stack starting with the low-order byte of the program counter (PCL) and ending with the CCR. After
stacking, the SP points at the next available location on the stack which is the address that is one less than
the address where the CCR was saved. The PC value that is stacked is the address of the instruction in the
main program that would have executed next if the interrupt had not occurred.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor63
Chapter 5 Resets, Interrupts, and System Configuration
UNSTACKING
ORDER
5
4
3
2
1
STACKING
ORDER
70
1
2
3
4
5
CONDITION CODE REGISTER
ACCUMULATOR
INDEX REGISTER (LOW BYTE X)
PROGRAM COUNTER HIGH
PROGRAM COUNTER LOW
* High byte (H) of index register is not automatically stacked.
TOWARD LOWER ADDRESSES
SP AFTER
INTERRUPT STACKING
*
SP BEFORE
THE INTERRUPT
TOWARD HIGHER ADDRESSES
Figure 5-1. Interrupt Stack Frame
When an RTI instruction is executed, these values are recovered from the stack in reverse order. As part of
the RTI sequence, the CPU fills the instruction pipeline by reading three bytes of program information,
starting from the PC address just recovered from the stack.
The status flag causing the interrupt must be acknowledged (cleared) before returning from the ISR.
Typically, the flag should be cleared at the beginning of the ISR so that if another interrupt is generated by
this same source, it will be registered so it can be serviced after completion of the current ISR.
5.5.2External Interrupt Request (IRQ) Pin
External interrupts are managed by the IRQSC status and control register. When the IRQ function is
enabled, synchronous logic monitors the pin for edge-only or edge-and-level events. When the MCU is in
stop mode and system clocks are shut down, a separate asynchronous path is used so the IRQ (if enabled)
can wake the MCU.
5.5.2.1Pin Configuration Options
The IRQ pin enable (IRQPE) control bit in the IRQSC register must be 1 for the IRQ pin to act as the
interrupt request (IRQ) input. When the pin is configured as an IRQ input, the user can choose the polarity
of edges or levels detected (IRQEDG), whether the pin detects edges-only or edges and levels (IRQMOD),
and whether an event causes an interrupt or only sets the IRQF flag (which can be polled by software).
When the IRQ pin is configured to detect rising edges, an optional pulldown resistor is available rather than
a pullup resistor. BIH and BIL instructions may be used to detect the level on the IRQ pin when the pin is
configured to act as the IRQ input.
NOTE
The voltage measured on the pulled up IRQ pin may be as low as V
V. The internal gates connected to this pin are pulled all the way to V
other pins with enabled pullup resistors will have an unloaded measurement
DD
.
of V
DD
DD
– 0.7
. All
MC9S08GB60A Data Sheet, Rev. 1.00
64Freescale Semiconductor
Chapter 5 Resets, Interrupts, and System Configuration
5.5.2.2Edge and Level Sensitivity
The IRQMOD control bit re-configures the detection logic so it detects edge events and pin levels. In this
edge detection mode, the IRQF status flag becomes set when an edge is detected (when the IRQ pin
changes from the deasserted to the asserted level), but the flag is continuously set (and cannot be cleared)
as long as the IRQ pin remains at the asserted level.
5.5.3Interrupt Vectors, Sources, and Local Masks
Table 5-1 provides a summary of all interrupt sources. Higher-priority sources are located toward the
bottom of the table. The high-order byte of the address for the interrupt service routine is located at the
first address in the vector address column, and the low-order byte of the address for the interrupt service
routine is located at the next higher address.
When an interrupt condition occurs, an associated flag bit becomes set. If the associated local interrupt
enable is 1, an interrupt request is sent to the CPU. Within the CPU, if the global interrupt mask (I bit in
the CCR) is 0, the CPU will finish the current instruction, stack the PCL, PCH, X, A, and CCR CPU
registers, set the I bit, and then fetch the interrupt vector for the highest priority pending interrupt.
Processing then continues in the interrupt service routine.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor65
Chapter 5 Resets, Interrupts, and System Configuration
Table 5-1. Vector Summary
Vector
Priority
Lower
Higher
Vector
Number
26
through
31
250xFFCC/FFCDVrtiSystem
240xFFCE/FFCFViic1IICIICISIICIEIIC control
230xFFD0/FFD1Vatd1ATDCOCOAIENAD conversion
Chapter 5 Resets, Interrupts, and System Configuration
5.6Low-Voltage Detect (LVD) System
The MC9S08GBxxA/GTxxA includes a system to protect against low voltage conditions to protect
memory contents and control MCU system states during supply voltage variations. The system comprises
a power-on reset (POR) circuit and an LVD circuit with a user selectable trip voltage, either high (V
or low (V
). The LVD circuit is enabled when LVDE in SPMSC1 is high and the trip voltage is selected
LVDL
by LVDV in SPMSC2. The LVD is disabled upon entering any of the stop modes unless the LVDSE bit is
set. If LVDSE and LVDE are both set, then the MCU cannot enter stop1 or stop2, and the current
consumption in stop3 with the LVD enabled will be greater.
5.6.1Power-On Reset Operation
LVDH
)
When power is initially applied to the MCU, or when the supply voltage drops below the V
POR
level, the
POR circuit will cause a reset condition. As the supply voltage rises, the LVD circuit will hold the chip in
reset until the supply has risen above the V
level. Both the POR bit and the LVD bit in SRS are set
LVDL
following a POR.
5.6.2LVD Reset Operation
The LVD can be configured to generate a reset upon detection of a low voltage condition by setting
LVDRE to 1. After an LVD reset has occurred, the LVD system will hold the MCU in reset until the supply
voltage has risen above the level determined by LVDV. The LVD bit in the SRS register is set following
either an LVD reset or POR.
5.6.3LVD Interrupt Operation
When a low voltage condition is detected and the LVD circuit is configured for interrupt operation (LVDE
set, LVDIE set, and LVDRE clear), then LVDF will be set and an LVD interrupt will occur.
5.6.4Low-Voltage Warning (LVW)
The LVD system has a low voltage warning flag to indicate to the user that the supply voltage is
approaching, but is still above, the LVD voltage. The LVW does not have an interrupt associated with it.
There are two user selectable trip voltages for the LVW, one high (V
voltage is selected by LVWV in SPMSC2.
) and one low (V
LVWH
LVWL
). The trip
5.7Real-Time Interrupt (RTI)
The real-time interrupt function can be used to generate periodic interrupts based on a multiple of the
source clock's period. The RTI has two source clock choices, the external clock input (ICGERCLK) to the
ICG or the RTI's own internal clock. The RTI can be used in run, wait, stop2 and stop3 modes. It is not
available in stop1 mode.
In run and wait modes, only the external clock can be used as the RTI's clock source. In stop2 mode, only
the internal RTI clock can be used. In stop3, either the external clock or internal RTI clock can be used.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor67
Chapter 5 Resets, Interrupts, and System Configuration
When using the external oscillator in stop3 mode, it must be enabled in stop (OSCSTEN = 1) and
configured for low bandwidth operation (RANGE = 0).
The SRTISC register includes a read-only status flag, a write-only acknowledge bit, and a 3-bit control
value (RTIS2:RTIS1:RTIS0) used to select one of seven RTI periods. The RTI has a local interrupt enable,
RTIE, to allow masking of the real-time interrupt. The module can be disabled by writing 0:0:0 to
RTIS2:RTIS1:RTIS0 in which case the clock source input is disabled and no interrupts will be generated.
See Section 5.8.6, “System Real-Time Interrupt Status and Control Register (SRTISC),” for detailed
information about this register.
5.8Reset, Interrupt, and System Control Registers and Control Bits
One 8-bit register in the direct page register space and eight 8-bit registers in the high-page register space
are related to reset and interrupt systems.
Refer to the direct-page register summary in Chapter 4, “Memory” of this data sheet for the absolute
address assignments for all registers. This section refers to registers and control bits only by their names.
A Freescale-provided equate or header file is used to translate these names into the appropriate absolute
addresses.
Some control bits in the SOPT and SPMSC2 registers are related to modes of operation. Although brief
descriptions of these bits are provided here, the related functions are discussed in greater detail in
Chapter 3, “Modes of Operation.”
MC9S08GB60A Data Sheet, Rev. 1.00
68Freescale Semiconductor
Chapter 5 Resets, Interrupts, and System Configuration
5.8.1Interrupt Pin Request Status and Control Register (IRQSC)
This direct page register includes two unimplemented bits which always read 0, four read/write bits, one
read-only status bit, and one write-only bit. These bits are used to configure the IRQ function, report status,
and acknowledge IRQ events.
76543210
R00
IRQEDGIRQPE
WIRQACK
Reset00000000
= Unimplemented or Reserved
Figure 5-2. Interrupt Request Status and Control Register (IRQSC)
Table 5-2. IRQSC Field Descriptions
FieldDescription
IRQF0
IRQIEIRQMOD
5
IRQEDG
4
IRQPE
3
IRQF
2
IRQACK
1
IRQIE
0
IRQMOD
Interrupt Request (IRQ) Edge Select — This read/write control bit is used to select the polarity of edges or
levels on the IRQ pin that cause IRQF to be set. The IRQMOD control bit determines whether the IRQ pin is
sensitive to both edges and levels or only edges. When the IRQ pin is enabled as the IRQ input and is configured
to detect rising edges, the optional pullup resistor is re-configured as an optional pulldown resistor.
0 IRQ is falling edge or falling edge/low-level sensitive.
1 IRQ is rising edge or rising edge/high-level sensitive.
IRQ Pin Enable — This read/write control bit enables the IRQ pin function. When this bit is set, the IRQ pin can
be used as an interrupt request. Also, when this bit is set, either an internal pull-up or an internal pull-down
resistor is enabled depending on the state of the IRQMOD bit.
0 IRQ pin function is disabled.
1 IRQ pin function is enabled.
IRQ Flag — This read-only status bit indicates when an interrupt request event has occurred.
0 No IRQ request.
1 IRQ event detected.
IRQ Acknowledge — This write-only bit is used to acknowledge interrupt request events (write 1 to clear IRQF).
Writing 0 has no meaning or effect. Reads always return 0. If edge-and-level detection is selected (IRQMOD = 1),
IRQF cannot be cleared while the IRQ pin remains at its asserted level.
IRQ Interrupt Enable — This read/write control bit determines whether IRQ events generate a hardware
interrupt request.
0 Hardware interrupt requests from IRQF disabled (use polling).
1 Hardware interrupt requested whenever IRQF = 1.
IRQ Detection Mode — This read/write control bit selects either edge-only detection or edge-and-level
detection. The IRQEDG control bit determines the polarity of edges and levels that are detected as interrupt
request events. See Section 5.5.2.2, “Edge and Level Sensitivity” for more details.
0 IRQ event on falling edges or rising edges only.
1 IRQ event on falling edges and low levels or on rising edges and high levels.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor69
Chapter 5 Resets, Interrupts, and System Configuration
5.8.2System Reset Status Register (SRS)
This register includes six read-only status flags to indicate the source of the most recent reset. When a
debug host forces reset by writing 1 to BDFR in the SBDFR register, none of the status bits in SRS will be
set. Writing any value to this register address clears the COP watchdog timer without affecting the contents
of this register. The reset state of these bits depends on what caused the MCU to reset.
76543210
R
PORPINCOPILOP
WWriting any value to SIMRS address clears COP watchdog timer.
0ICGLVD0
Power-on
reset:
Low-voltage
reset:
Any other
reset:
1
Any of these reset sources that are active at the time of reset will cause the corresponding bit(s) to be set; bits corresponding to
sources that are not active at the time of reset will be cleared.
10000010
U0000010
0Note
U = Unaffected by reset
(1)
Note
(1)
Note
(1)
0Note
(1)
00
Figure 5-3. System Reset Status (SRS)
Table 5-3. SRS Field Descriptions
FieldDescription
7
POR
6
PIN
Power-On Reset — Reset was caused by the power-on detection logic. Because the internal supply voltage was
ramping up at the time, the low-voltage reset (LVD) status bit is also set to indicate that the reset occurred while
the internal supply was below the LVD threshold.
0 Reset not caused by POR.
1 POR caused reset.
External Reset Pin — Reset was caused by an active-low level on the external reset pin.
0 Reset not caused by external reset pin.
1 Reset came from external reset pin.
5
COP
4
ILOP
70Freescale Semiconductor
Computer Operating Properly (COP) Watchdog — Reset was caused by the COP watchdog timer timing out.
This reset source may be blocked by COPE = 0.
0 Reset not caused by COP timeout.
1 Reset caused by COP timeout.
Illegal Opcode — Reset was caused by an attempt to execute an unimplemented or illegal opcode. The STOP
instruction is considered illegal if stop is disabled by STOPE = 0 in the SOPT register. The BGND instruction is
considered illegal if active background mode is disabled by ENBDM = 0 in the BDCSC register.
0 Reset not caused by an illegal opcode.
1 Reset caused by an illegal opcode.
MC9S08GB60A Data Sheet, Rev. 1.00
Chapter 5 Resets, Interrupts, and System Configuration
Table 5-3. SRS Field Descriptions (continued)
FieldDescription
2
ICG
1
LV D
Internal Clock Generation Module Reset — Reset was caused by an ICG module reset.
0 Reset not caused by ICG module.
1 Reset caused by ICG module.
Low Voltage Detect — If the LVD reset is enabled (LVDE = LVDRE = 1) and the supply drops below the LVD trip
voltage, an LVD reset occurs. The LVD function is disabled when the MCU enters stop. To maintain LVD operation
in stop, the LVDSE bit must be set.
0 Reset not caused by LVD trip or POR.
1 Reset caused by LVD trip or POR.
5.8.3System Background Debug Force Reset Register (SBDFR)
This register contains a single write-only control bit. A serial background command such as
WRITE_BYTE must be used to write to SBDFR. Attempts to write this register from a user program are
ignored. Reads always return 0x00.
76543210
R00000000
WBDFR
Reset00000000
= Unimplemented or Reserved
1
BDFR is writable only through serial background debug commands, not from user programs.
1
Figure 5-4. System Background Debug Force Reset Register (SBDFR)
Table 5-4. SBDFR Field Descriptions
FieldDescription
0
BDFR
Background Debug Force Reset — A serial background mode command such as WRITE_BYTE allows an
external debug host to force a target system reset. Writing 1 to this bit forces an MCU reset. This bit cannot be
written from a user program.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor71
Chapter 5 Resets, Interrupts, and System Configuration
5.8.4System Options Register (SOPT)
This register may be read at any time. Bits 3 and 2 are unimplemented and always read 0. This is a
write-once register so only the first write after reset is honored. Any subsequent attempt to write to SOPT
(intentionally or unintentionally) is ignored to avoid accidental changes to these sensitive settings. SOPT
should be written during the user’s reset initialization program to set the desired controls even if the desired
settings are the same as the reset settings.
76543210
R
COPECOPTSTOPE
W
Reset11010011
= Unimplemented or Reserved
Figure 5-5. System Options Register (SOPT)
Table 5-5. SOPT Field Descriptions
FieldDescription
00
BKGDPE
7
COPE
6
COPT
5
STOPE
1
BKGDPE
COP Watchdog Enable — This write-once bit defaults to 1 after reset.
0 COP watchdog timer disabled.
1 COP watchdog timer enabled (force reset on timeout).
COP Watchdog Timeout — This write-once bit defaults to 1 after reset.
0 Short timeout period selected (2
1 Long timeout period selected (2
Stop Mode Enable — This write-once bit defaults to 0 after reset, which disables stop mode. If stop mode is
disabled and a user program attempts to execute a STOP instruction, an illegal opcode reset is forced.
0 Stop mode disabled.
1 Stop mode enabled.
Background Debug Mode Pin Enable — The BKGDPE bit enables the PTG0/BKGD/MS pin to function as
BKGD/MS. When the bit is clear, the pin will function as PTG0, which is an output-only general-purpose I/O. This
pin always defaults to BKGD/MS function after any reset.
0 BKGD pin disabled.
1 BKGD pin enabled.
13
cycles of BUSCLK).
18
cycles of BUSCLK).
MC9S08GB60A Data Sheet, Rev. 1.00
72Freescale Semiconductor
Chapter 5 Resets, Interrupts, and System Configuration
This read-only register is included so host development systems can identify the HCS08 derivative and
revision number. This allows the development software to recognize where specific memory blocks,
registers, and control bits are located in a target MCU.
76543210
RREV3REV2REV1REV0ID11ID10ID9ID8
W
Reset0
1
The revision number that is hard coded into these bits reflects the current silicon revision level.
FieldDescription
1
(1)
0
= Unimplemented or Reserved
(1)
0
(1)
0
0000
Figure 5-6. System Device Identification Register High (SDIDH)
Table 5-6. SDIDH Field Descriptions
7:4
REV[3:0]
3:0
ID[11:8]
RID7ID6ID5ID4ID3ID2ID1ID0
W
Reset00000010
Revision Number — The high-order 4 bits of address 0x1806 are hard coded to reflect the current mask set
revision number (0–F).
Part Identification Number — Each derivative in the HCS08 Family has a unique identification number. The
MC9S08GBxxA/GTxxA is hard coded to the value 0x002. See also ID bits in Table 5-7.
76543210
= Unimplemented or Reserved
Figure 5-7. System Device Identification Register Low (SDIDL)
Table 5-7. SDIDL Field Descriptions
FieldDescription
3:0
ID[7:0]
Part Identification Number — Each derivative in the HCS08 Family has a unique identification number. The
MC9S08GBxxA/GTxxA is hard coded to the value 0x002. See also ID bits in Table 5-6.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor73
Chapter 5 Resets, Interrupts, and System Configuration
5.8.6System Real-Time Interrupt Status and Control Register (SRTISC)
This register contains one read-only status flag, one write-only acknowledge bit, three read/write delay
selects, and three unimplemented bits, which always read 0.
76543210
R
RTIF
0
RTICLKSRTIE
W
RTIACK
Reset00000000
= Unimplemented or Reserved
Figure 5-8. System RTI Status and Control Register (SRTISC)
Table 5-8. SRTISC Field Descriptions
FieldDescription
0
RTIS2RTIS1RTIS0
7
RTIF
Real-Time Interrupt Flag — This read-only status bit indicates the periodic wakeup timer has timed out.
0 Periodic wakeup timer not timed out.
1 Periodic wakeup timer timed out.
6
RTIACK
5
RTICLKS
Real-Time Interrupt Acknowledge — This write-only bit is used to acknowledge real-time interrupt request
(write 1 to clear RTIF). Writing 0 has no meaning or effect. Reads always return 0.
Real-Time Interrupt Clock Select — This read/write bit selects the clock source for the real-time interrupt.
0 Real-time interrupt request clock source is internal oscillator.
1 Real-time interrupt request clock source is external clock.
4
RTIE
Real-Time Interrupt Enable — This read-write bit enables real-time interrupts.
0 Real-time interrupts disabled.
1 Real-time interrupts enabled.
2:0
RTIS[2:0]
Real-Time Interrupt Period Selects — These read/write bits select the wakeup period for the RTI. One clock
source for the real-time interrupt is its own internal clock source, which oscillates with a period of approximately
t
and is independent of other MCU clock sources. Using an external clock source the delays will be crystal
RTI
frequency divided by value in RTIS2:RTIS1:RTIS0. See Table 5-9.
is based on the external clock source, resonator, or crystal selected by the ICG configuration. See Table A-9 for details.
ext
in Appendix A, “Electrical Characteristics,” for the tolerance on these values.
RTI
1
External Clock Source
Period = t
t
ext
t
ex
t
ex
t
ex
t
ext
t
ext
t
ex
ext
x 256
x 1024
x 2048
x 4096
x 8192
x 16384
x 32768
2
MC9S08GB60A Data Sheet, Rev. 1.00
74Freescale Semiconductor
Chapter 5 Resets, Interrupts, and System Configuration
5.8.7System Power Management Status and Control 1 Register (SPMSC1)
76543210
RLVDF0
LVDIELVDRE
1
LVDSE
(1)
LVDE
(1)
WLVD AC K
Reset00011100
= Unimplemented or Reserved
1
This bit can be written only one time after reset. Additional writes are ignored.
Figure 5-9. System Power Management Status and Control 1 Register (SPMSC1)
Table 5-10. SPMSC1 Field Descriptions
FieldDescription
00
7
LVDF
6
LV DAC K
5
LVDIE
4
LVDRE
3
LVDSE
2
LVDE
Low-Voltage Detect Flag — Provided LVDE = 1, this read-only status bit indicates a low-voltage detect event.
Low-Voltage Detect Acknowledge — This write-only bit is used to acknowledge low voltage detection errors
(write 1 to clear LVDF). Reads always return 0.
Low-Voltage Detect Interrupt Enable — This read/write bit enables hardware interrupt requests for LVDF.
0 Hardware interrupt disabled (use polling).
1 Request a hardware interrupt when LVDF = 1.
Low-Voltage Detect Reset Enable — This read/write bit enables LVDF events to generate a hardware reset
(provided LVDE = 1).
0 LVDF does not generate hardware resets.
1 Force an MCU reset when LVDF = 1.
Low-Voltage Detect Stop Enable — Provided LVDE = 1, this read/write bit determines whether the low-voltage
detect function operates when the MCU is in stop mode.
0 Low-voltage detect disabled during stop mode.
1 Low-voltage detect enabled during stop mode.
Low-Voltage Detect Enable — This read/write bit enables low-voltage detect logic and qualifies the operation
of other bits in this register.
0 LVD logic disabled.
1 LVD logic enabled.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor75
Chapter 5 Resets, Interrupts, and System Configuration
5.8.8System Power Management Status and Control 2 Register (SPMSC2)
This register is used to report the status of the low voltage warning function, and to configure the stop mode
behavior of the MCU.
76543210
R
LVWF
W
Power-on
(1)
0
reset:
LVD reset:0
Any other
(1)
(1)
0
reset:
1
LVWF will be set in the case when V
Figure 5-10. System Power Management Status and Control 2 Register (SPMSC2)
0
LV WAC KPPDACK
0000000
0UU0000
0UU0000
= Unimplemented or ReservedU = Unaffected by reset
Supply
LV DVLV WV
transitions below the trip point or after reset and V
PPDF
0
is already below V
Supply
PDCPPDC
LV W
.
Table 5-11. SPMSC2 Field Descriptions
FieldDescription
7
LVWF
6
LV WAC K
5
LV DV
4
LVWV
3
PPDF
2
PPDACK
1
PDC
Low-Voltage Warning Flag — The LVWF bit indicates the low voltage warning status.
0 Low voltage warning not present.
1 Low voltage warning is present or was present.
Low-Voltage Warning Acknowledge — The LVWACK bit is the low-voltage warning acknowledge. Writing a 1
to LVWACK clears LVWF to 0 if a low voltage warning is not present.
Low-Voltage Detect Voltage Select — The LVDV bit selects the LVD trip point voltage (V
0 Low trip point selected (V
1 High trip point selected (V
LV D
LV D
= V
= V
LVDL
LVDH
).
).
Low-Voltage Warning Voltage Select — The LVWV bit selects the LVW trip point voltage (V
0 Low trip point selected (V
1 High trip point selected (V
LV W
LV W
= V
= V
LVWL
LVWH
).
).
Partial Power Down Flag — The PPDF bit indicates that the MCU has exited the stop2 mode.
0 Not stop2 mode recovery.
1 Stop2 mode recovery.
Partial Power Down Acknowledge — Writing a 1 to PPDACK clears the PPDF bit.
Power Down Control — The write-once PDC bit controls entry into the power down (stop2 and stop1) modes.
0 Power down modes are disabled.
1 Power down modes are enabled.
LV D
).
LV W
).
0
PPDC
Partial Power Down Control — The write-once PPDC bit controls which power down mode, stop1 or stop2, is
selected.
0 Stop1, full power down, mode enabled if PDC set.
1 Stop2, partial power down, mode enabled if PDC set.
MC9S08GB60A Data Sheet, Rev. 1.00
76Freescale Semiconductor
Chapter 6
Parallel Input/Output
6.1Introduction
This section explains software controls related to parallel input/output (I/O). The MC9S08GBxxA has
seven I/O ports which include a total of 56 general-purpose I/O pins (one of these pins is output only). The
MC9S08GTxxA has six I/O ports which include a total of up to 39 general-purpose I/O pins (one pin,
PTG0, is output only). See Chapter 2, “Pins and Connections,” for more information about the logic and
hardware aspects of these pins.
Many of these pins are shared with on-chip peripherals such as timer systems, external interrupts, or
keyboard interrupts. When these other modules are not controlling the port pins, they revert to
general-purpose I/O control. For each I/O pin, a port data bit provides access to input (read) and output
(write) data, a data direction bit controls the direction of the pin, and a pullup enable bit enables an internal
pullup device (provided the pin is configured as an input), and a slew rate control bit controls the rise and
fall times of the pins.
NOTE
Not all general-purpose I/O pins are available on all packages. To avoid
extra current drain from floating input pins, the user’s reset initialization
routine in the application program should either enable on-chip pullup
devices or change the direction of unconnected pins to outputs so the pins
do not float.
Parallel I/O features, depending on package choice, include:
•A total of 56 general-purpose I/O pins in seven ports (PTG0 is output only)
•High-current drivers on port C and port F pins
•Hysteresis input buffers
•Software-controlled pullups on each input pin
•Software-controlled slew rate output buffers
•Eight port A pins shared with KBI1
•Eight port B pins shared with ATD1
•Eight high-current port C pins shared with SCI2 and IIC1
•Eight port D pins shared with TPM1 and TPM2
•Eight port E pins shared with SCI1 and SPI1
•Eight high-current port F pins
•Eight port G pins shared with EXTAL, XTAL, and BKGD/MS
6.3Pin Descriptions
Chapter 6 Parallel Input/Output
The MC9S08GBxxA/GTxxA has a total of 56 parallel I/O pins (one is output only) in seven 8-bit ports
(PTA–PTG). Not all pins are bonded out in all packages. Consult the pin assignment in Chapter 2, “Pins
and Connections,” for available parallel I/O pins. All of these pins are available for general-purpose I/O
when they are not used by other on-chip peripheral systems.
After reset, BKGD/MS is enabled and therefore is not usable as an output pin until BKGDPE in SOPT is
cleared. The rest of the peripheral functions are disabled. After reset, all data direction and pullup enable
controls are set to 0s. These pins default to being high-impedance inputs with on-chip pullup devices
disabled.
The following paragraphs discuss each port and the software controls that determine each pin’s use.
6.3.1Port A and Keyboard Interrupts
Port ABit 7654321Bit 0
MCU Pin:
PTA7/
KBI1P7
Port A is an 8-bit port shared among the KBI keyboard interrupt inputs and general-purpose I/O. Any pins
enabled as KBI inputs will be forced to act as inputs.
PTA6/
KBI1P6
Figure 6-2. Port A Pin Names
PTA5/
KBI1P5
PTA4/
KBI1P4
PTA3/
KBI1P3
PTA2/
KBI1P2
PTA1/
KBI1P1
PTA0/
KBI1P0
Port A pins are available as general-purpose I/O pins controlled by the port A data (PTAD), data direction
(PTADD), pullup enable (PTAPE), and slew rate control (PTASE) registers. Refer to Section 6.4, “Parallel
I/O Controls,” for more information about general-purpose I/O control.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor79
Chapter 6 Parallel Input/Output
Port A can be configured to be keyboard interrupt input pins. Refer to Chapter 9, “Keyboard Interrupt
(S08KBIV1),” for more information about using port A pins as keyboard interrupts pins.
6.3.2Port B and Analog to Digital Converter Inputs
j
Port BBit 7654321Bit 0
MCU Pin:
PTB7/
AD1P7
PTB6/
AD1P6
Figure 6-3. Port B Pin Names
PTB5/
AD1P5
PTB4/
AD1P4
PTB3/
AD1P3
PTB2/
AD1P2
PTB1/
AD1P1
PTB0/
AD1P0
Port B is an 8-bit port shared among the ATD inputs and general-purpose I/O. Any pin enabled as an ATD
input will be forced to act as an input.
Port B pins are available as general-purpose I/O pins controlled by the port B data (PTBD), data direction
(PTBDD), pullup enable (PTBPE), and slew rate control (PTBSE) registers. Refer to Section 6.4, “Parallel
I/O Controls,” for more information about general-purpose I/O control.
When the ATD module is enabled, analog pin enables are used to specify which pins on port B will be used
as ATD inputs. Refer to Chapter 14, “Analog-to-Digital Converter (S08ATDV3),” for more information
about using port B pins as ATD pins.
6.3.3Port C and SCI2, IIC, and High-Current Drivers
Port CBit 7653321Bit 0
MCU Pin:PTC7PTC6PTC5PTC4
Figure 6-4. Port C Pin Names
PTC3/
SCL1
PTC2/
SDA1
PTC1/
RxD2
PTC0/
TxD2
Port C is an 8-bit port which is shared among the SCI2 and IIC1 modules, and general-purpose I/O. When
SCI2 or IIC1 modules are enabled, the pin direction will be controlled by the module or function. Port C
has high current output drivers.
Port C pins are available as general-purpose I/O pins controlled by the port C data (PTCD), data direction
(PTCDD), pullup enable (PTCPE), and slew rate control (PTCSE) registers. Refer to Section 6.4, “Parallel
I/O Controls,” for more information about general-purpose I/O control.
When the SCI2 module is enabled, PTC0 serves as the SCI2 module’s transmit pin (TxD2) and PTC1
serves as the receive pin (RxD2). Refer to Chapter 11, “Serial Communications Interface (S08SCIV1),”
for more information about using PTC0 and PTC1 as SCI pins
When the IIC module is enabled, PTC2 serves as the IIC modules’s serial data input/output pin (SDA1)
and PTC3 serves as the clock pin (SCL1). Refer to Chapter 13, “Inter-Integrated Circuit (S08IICV1),” for
more information about using PTC2 and PTC3 as IIC pins.
MC9S08GB60A Data Sheet, Rev. 1.00
80Freescale Semiconductor
Chapter 6 Parallel Input/Output
6.3.4Port D, TPM1 and TPM2
Port DBit 7654321Bit 0
MCU Pin:
PTD7/
TPM2CH4
PTD6/
TPM2CH3
Figure 6-5. Port D Pin Names
PTD5/
TPM2CH2
PTD4/
TPM2CH1
PTD3/
TPM2CH0
PTD2/
TPM1CH2
PTD1/
TPM1CH1
PTD0/
TPM1CH0
Port D is an 8-bit port shared with the two TPM modules, TPM1 and TPM2, and general-purpose I/O.
When the TPM1 or TPM2 modules are enabled in output compare or input capture modes of operation,
the pin direction will be controlled by the module function.
Port D pins are available as general-purpose I/O pins controlled by the port D data (PTDD), data direction
(PTDDD), pullup enable (PTDPE), and slew rate control (PTDSE) registers. Refer to Section 6.4, “Parallel
I/O Controls” for more information about general-purpose I/O control.
The TPM2 module can be configured to use PTD7–PTD3 as either input capture, output compare, PWM,
or external clock input pins (PTD3 only). Refer to Chapter 10, “Timer/PWM (S08TPMV1)” for more
information about using PTD7–PTD3 as timer pins.
The TPM1 module can be configured to use PTD2–PTD0 as either input capture, output compare, PWM,
or external clock input pins (PTD0 only). Refer to Chapter 10, “Timer/PWM (S08TPMV1)” for more
information about using PTD2–PTD0 as timer pins.
6.3.5Port E, SCI1, and SPI
Port EBit 7654321Bit 0
MCU Pin:PTE7PTE6
Figure 6-6. Port E Pin Names
PTE5/
SPSCK1
PTE4/
MOSI1
PTE3/
MISO1
PTE2/
SS1
PTE1/
RxD1
PTE0/
TxD1
Port E is an 8-bit port shared with the SCI1 module, SPI1 module, and general-purpose I/O. When the SCI
or SPI modules are enabled, the pin direction will be controlled by the module function.
Port E pins are available as general-purpose I/O pins controlled by the port E data (PTED), data direction
(PTEDD), pullup enable (PTEPE), and slew rate control (PTESE) registers. Refer to Section 6.4, “Parallel
I/O Controls” for more information about general-purpose I/O control.
When the SCI1 module is enabled, PTE0 serves as the SCI1 module’s transmit pin (TxD1) and PTE1
serves as the receive pin (RxD1). Refer to Chapter 11, “Serial Communications Interface (S08SCIV1)” for
more information about using PTE0 and PTE1 as SCI pins.
When the SPI module is enabled, PTE2 serves as the SPI module’s slave select pin (
SS1), PTE3 serves as
the master-in slave-out pin (MISO1), PTE4 serves as the master-out slave-in pin (MOSI1), and PTE5
serves as the SPI clock pin (SPSCK1). Refer to Chapter 12, “Serial Peripheral Interface (S08SPIV3) for
more information about using PTE5–PTE2 as SPI pins.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor81
Chapter 6 Parallel Input/Output
6.3.6Port F and High-Current Drivers
Port FBit 7654321Bit 0
MCU Pin:PTF7PTF6PTF5PTF4PTF3PTF2PTF1PTF0
Figure 6-7. Port F Pin Names
Port F is an 8-bit port general-purpose I/O that is not shared with any peripheral module. Port F has high
current output drivers.
Port F pins are available as general-purpose I/O pins controlled by the port F data (PTFD), data direction
(PTFDD), pullup enable (PTFPE), and slew rate control (PTFSE) registers. Refer to Section 6.4, “Parallel
I/O Controls” for more information about general-purpose I/O control.
6.3.7Port G, BKGD/MS, and Oscillator
Port GBit 7654321Bit 0
MCU Pin:PTG7PTG6PTG5PTG4PTG3
Figure 6-8. Port G Pin Names
PTG2/
EXTAL
PTG1/
XTAL
PTG0/
BKGD/MS
Port G is an 8-bit port which is shared among the background/mode select function, oscillator, and
general-purpose I/O. When the background/mode select function or oscillator is enabled, the pin direction
will be controlled by the module function.
Port G pins are available as general-purpose I/O pins controlled by the port G data (PTGD), data direction
(PTGDD), pullup enable (PTGPE), and slew rate control (PTGSE) registers. Refer to Section 6.4, “Parallel
I/O Controls” for more information about general-purpose I/O control.
The internal pullup for PTG0 is enabled when the background/mode select function is enabled, regardless
of the state of PTGPE0. During reset, the BKGD/MS pin functions as a mode select pin. After the MCU
is out of reset, the BKGD/MS pin becomes the background communications input/output pin. The PTG0
can be configured to be a general-purpose output pin. Refer to Chapter 3, “Modes of Operation”,
Chapter 5, “Resets, Interrupts, and System Configuration”, and Chapter 15, “Development Support” for
more information about using this pin.
The ICG module can be configured to use PTG2–PTG1 ports as crystal oscillator or external clock pins.
Refer to Chapter 13, “Inter-Integrated Circuit (S08IICV1)” for more information about using these pins as
oscillator pins.
MC9S08GB60A Data Sheet, Rev. 1.00
82Freescale Semiconductor
Chapter 6 Parallel Input/Output
6.4Parallel I/O Controls
Provided no on-chip peripheral is controlling a port pin, the pins operate as general-purpose I/O pins that
are accessed and controlled by a data register (PTxD), a data direction register (PTxDD), a pullup enable
register (PTxPE), and a slew rate control register (PTxSE) where x is A, B, C, D, E, F, or G.
Reads of the data register return the pin value (if PTxDDn = 0) or the contents of the port data register (if
PTxDDn = 1). Writes to the port data register are latched into the port register whether the pin is controlled
by an on-chip peripheral or the pin is configured as an input. If the corresponding pin is not controlled by
a peripheral and is configured as an output, this level will be driven out the port pin.
6.4.1Data Direction Control
The data direction control bits determine whether the pin output driver is enabled, and they control what
is read for port data register reads. Each port pin has a data direction control bit. When PTxDDn = 0, the
corresponding pin is an input and reads of PTxD return the pin value. When PTxDDn = 1, the
corresponding pin is an output and reads of PTxD return the last value written to the port data register.
When a peripheral module or system function is in control of a port pin, the data direction control still
controls what is returned for reads of the port data register, even though the peripheral system has
overriding control of the actual pin direction.
For the MC9S08GBxxA/GTxxA MCU, reads of PTG0/BKGD/MS will return the value on the output pin.
It is a good programming practice to write to the port data register before changing the direction of a port
pin to become an output. This ensures that the pin will not be driven momentarily with an old data value
that happened to be in the port data register.
6.4.2Internal Pullup Control
An internal pullup device can be enabled for each port pin that is configured as an input (PTxDDn = 0).
The pullup device is available for a peripheral module to use, provided the peripheral is enabled and is an
input function as long as the PTxDDn = 0.
For the four configurable KBI module inputs on PTA7–PTA4, when a pin is configured to detect rising
edges, the port pullup enable associated with the pin (PTAPEn) selects a pulldown rather than a pullup
device.
6.4.3Slew Rate Control
Slew rate control can be enabled for each port pin that is configured as an output (PTxDDn = 1) or if a
peripheral module is enabled and its function is an output. Not all peripheral modules’ outputs have slew
rate control; refer to Chapter 2, “Pins and Connections” for more information about which pins have slew
rate control.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor83
Chapter 6 Parallel Input/Output
6.5Stop Modes
Depending on the stop mode, I/O functions differently as the result of executing a STOP instruction. An
explanation of I/O behavior for the various stop modes follows:
•When the MCU enters stop1 mode, all internal registers including general-purpose I/O control and
data registers are powered down. All of the general-purpose I/O pins assume their reset state:
output buffers and pullups turned off. Upon exit from stop1, all I/O must be initialized as if the
MCU had been reset.
•When the MCU enters stop2 mode, the internal registers are powered down as in stop1 but the I/O
pin states are latched and held. For example, a port pin that is an output driving low continues to
function as an output driving low even though its associated data direction and output data registers
are powered down internally. Upon exit from stop2, the pins continue to hold their states until a 1
is written to the PPDACK bit. To avoid discontinuity in the pin state following exit from stop2, the
user must restore the port control and data registers to the values they held before entering stop2.
These values can be stored in RAM before entering stop2 because the RAM is maintained during
stop2.
•In stop3 mode, all I/O is maintained because internal logic circuity stays powered up. Upon
recovery, normal I/O function is available to the user.
6.6Parallel I/O Registers and Control Bits
This section provides information about all registers and control bits associated with the parallel I/O ports.
Refer to tables in Chapter 4, “Memory” for the absolute address assignments for all parallel I/O registers.
This section refers to registers and control bits only by their names. A Freescale-provided equate or header
file normally is used to translate these names into the appropriate absolute addresses.
6.6.1Port A Registers (PTAD, PTAPE, PTASE, and PTADD)
Port A includes eight pins shared between general-purpose I/O and the KBI module. Port A pins used as
general-purpose I/O pins are controlled by the port A data (PTAD), data direction (PTADD), pullup enable
(PTAPE), and slew rate control (PTASE) registers.
If the KBI takes control of a port A pin, the corresponding PTASE bit is ignored since the pin functions as
an input. As long as PTADD is 0, the PTAPE controls the pullup enable for the KBI function. Reads of
PTAD will return the logic value of the corresponding pin, provided PTADD is 0.
MC9S08GB60A Data Sheet, Rev. 1.00
84Freescale Semiconductor
Chapter 6 Parallel Input/Output
76543210
R
PTAD7PTAD6PTAD5PTAD4PTAD3PTAD2PTAD1PTAD0
W
Reset00000000
Figure 6-9. Port A Data Register (PTAD)
Table 6-1. PTAD Field Descriptions
FieldDescription
7:0
PTAD[7:0]
Port A Data Register Bits — For port A pins that are inputs, reads return the logic level on the pin. For port A
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For port A pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTAD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures
all port pins as high-impedance inputs with pullups disabled.
76543210
R
PTAPE7PTAPE6PTAPE5PTAPE4PTAPE3PTAPE2PTAPE1PTAPE0
W
Reset00000000
Figure 6-10. Pullup Enable for Port A (PTAPE)
Table 6-2. PTAPE Field Descriptions
FieldDescription
7:0
PTAPE[7:0]
Pullup Enable for Port A Bits — For port A pins that are inputs, these read/write control bits determine whether
internal pullup devices are enabled provided the corresponding PTADDn is 0. For port A pins that are configured
as outputs, these bits are ignored and the internal pullup devices are disabled. When any of bits 7 through 4 of
port A are enabled as KBI inputs and are configured to detect rising edges/high levels, the pullup enable bits
enable pulldown rather than pullup devices.
0 Internal pullup device disabled.
1 Internal pullup device enabled.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor85
Chapter 6 Parallel Input/Output
76543210
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PTASE7PTASE6PTASE5PTASE4PTASE3PTASE2PTASE1PTASE0
W
Reset00000000
Figure 6-11. Slew Rate Control Enable for Port A (PTASE)
Table 6-3. PTASE Field Descriptions
FieldDescription
7:0
PTASE[7:0]
Slew Rate Control Enable for Port A Bits — For port A pins that are outputs, these read/write control bits
determine whether the slew rate controlled outputs are enabled. For port A pins that are configured as inputs,
these bits are ignored.
0 Slew rate control disabled.
1 Slew rate control enabled.
76543210
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PTADD7PTADD6PTADD5PTADD4PTADD3PTADD2PTADD1PTADD0
W
Reset00000000
Figure 6-12. Data Direction for Port A (PTADD)
Table 6-4. PTADD Field Descriptions
FieldDescription
7:0
PTADD[7:0]
Data Direction for Port A Bits — These read/write bits control the direction of port A pins and what is read for
PTAD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for port A bit n and PTAD reads return the contents of PTADn.
MC9S08GB60A Data Sheet, Rev. 1.00
86Freescale Semiconductor
Chapter 6 Parallel Input/Output
6.6.2Port B Registers (PTBD, PTBPE, PTBSE, and PTBDD)
Port B includes eight general-purpose I/O pins that share with the ATD function. Port B pins used as
general-purpose I/O pins are controlled by the port B data (PTBD), data direction (PTBDD), pullup enable
(PTBPE), and slew rate control (PTBSE) registers.
If the ATD takes control of a port B pin, the corresponding PTBDD, PTBSE, and PTBPE bits are ignored.
When a port B pin is being used as an ATD pin, reads of PTBD will return a 0 of the corresponding pin,
provided PTBDD is 0.
76543210
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PTBD7PTBD6PTBD5PTBD4PTBD3PTBD2PTBD1PTBD0
W
Reset00000000
Figure 6-13. Port B Data Register (PTBD)
Table 6-5. PTBD Field Descriptions
FieldDescription
7:0
PTBD[7:0]
R
W
Reset00000000
Port B Data Register Bits — For port B pins that are inputs, reads return the logic level on the pin. For port B
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For port B pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTBD to all 0s, but these 0s are not driven out on the corresponding pins because reset also
configures all port pins as high-impedance inputs with pullups disabled.
76543210
PTBPE7PTBPE6PTBPE5PTBPE4PTBPE3PTBPE2PTBPE1PTBPE0
Figure 6-14. Pullup Enable for Port B (PTBPE)
Table 6-6. PTBPE Field Descriptions
FieldDescription
7:0
PTBPE[7:0]
Pullup Enable for Port B Bits — For port B pins that are inputs, these read/write control bits determine whether
internal pullup devices are enabled. For port B pins that are configured as outputs, these bits are ignored and
the internal pullup devices are disabled.
0 Internal pullup device disabled.
1 Internal pullup device enabled.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor87
Chapter 6 Parallel Input/Output
76543210
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PTBSE7PTBSE6PTBSE5PTBSE4PTBSE3PTBSE2PTBSE1PTBSE0
W
Reset00000000
Figure 6-15. Data Direction for Port A (PTBSE)
Table 6-7. PTBSE Field Descriptions
FieldDescription
7:0
PTBSE[7:0]
Slew Rate Control Enable for Port B Bits — For port B pins that are outputs, these read/write control bits
determine whether the slew rate controlled outputs are enabled. For port B pins that are configured as inputs,
these bits are ignored.
0 Slew rate control disabled.
1 Slew rate control enabled.
76543210
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PTBDD7PTBDD6PTBDD5PTBDD4PTBDD3PTBDD2PTBDD1PTBDD0
W
Reset00000000
Figure 6-16. Data Direction for Port B (PTBDD)
Table 6-8. PTBDD Field Descriptions
FieldDescription
7:0
PTBDD[7:0]
Data Direction for Port B Bits — These read/write bits control the direction of port B pins and what is read for
PTBD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for port B bit n and PTBD reads return the contents of PTBDn.
MC9S08GB60A Data Sheet, Rev. 1.00
88Freescale Semiconductor
Chapter 6 Parallel Input/Output
6.6.3Port C Registers (PTCD, PTCPE, PTCSE, and PTCDD)
Port C includes eight general-purpose I/O pins that share with the SCI2 and IIC modules. Port C pins used
as general-purpose I/O pins are controlled by the port C data (PTCD), data direction (PTCDD), pullup
enable (PTCPE), and slew rate control (PTCSE) registers.
If the SCI2 takes control of a port C pin, the corresponding PTCDD bit is ignored. PTCSE can be used to
provide slew rate on the SCI2 transmit pin, TxD2. PTCPE can be used, provided the corresponding
PTCDD bit is 0, to provide a pullup device on the SCI2 receive pin, RxD2.
If the IIC takes control of a port C pin, the corresponding PTCDD bit is ignored. PTCSE can be used to
provide slew rate on the IIC serial data pin (SDA1), when in output mode and the IIC clock pin (SCL1).
PTCPE can be used, provided the corresponding PTCDD bit is 0, to provide a pullup device on the IIC
serial data pin, when in receive mode.
Reads of PTCD will return the logic value of the corresponding pin, provided PTCDD is 0.
76543210
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PTCD7PTCD6PTCD5PTCD4PTCD3PTCD2PTCD1PTCD0
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Reset00000000
Figure 6-17. Port C Data Register (PTCD)
Table 6-9. PTCD Field Descriptions
FieldDescription
7:0
PTCD[7:0]
Port C Data Register Bits— For port C pins that are inputs, reads return the logic level on the pin. For port C
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For port C pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTCD to all 0s, but these 0s are not driven out the corresponding pins because reset also
configures all port pins as high-impedance inputs with pullups disabled.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor89
Chapter 6 Parallel Input/Output
76543210
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PTCPE7PTCPE6PTCPE5PTCPE4PTCPE3PTCPE2PTCPE1PTCPE0
W
Reset00000000
Figure 6-18. Pullup Enable for Port C (PTCPE)
Table 6-10. PTCPE Field Descriptions
FieldDescription
7:0
PTCPE[7:0]
Pullup Enable for Port C Bits — For port C pins that are inputs, these read/write control bits determine whether
internal pullup devices are enabled. For port C pins that are configured as outputs, these bits are ignored and
the internal pullup devices are disabled.
0 Internal pullup device disabled.
1 Internal pullup device enabled.
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PTCSE7PTCSE6PTCSE5PTCSE4PTCSE3PTCSE2PTCSE1PTCSE0
W
Reset00000000
Figure 6-19. Slew Rate Control Enable for Port C (PTCSE)
Table 6-11. PTCSE Field Descriptions
FieldDescription
7:0
PTCSE[7:0]
Slew Rate Control Enable for Port C Bits — For port C pins that are outputs, these read/write control bits
determine whether the slew rate controlled outputs are enabled. For port B pins that are configured as inputs,
these bits are ignored.
0 Slew rate control disabled.
1 Slew rate control enabled.
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PTCDD7PTCDD6PTCDD5PTCDD4PTCDD3PTCDD2PTCDD1PTCDD0
W
Reset00000000
Figure 6-20. Data Direction for Port C (PTCDD)
Table 6-12. PTCDD Field Descriptions
FieldDescription
7:0
PTCDD[7:0]
90Freescale Semiconductor
Data Direction for Port C Bits — These read/write bits control the direction of port C pins and what is read for
PTCD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for port C bit n and PTCD reads return the contents of PTCDn.
MC9S08GB60A Data Sheet, Rev. 1.00
Chapter 6 Parallel Input/Output
6.6.4Port D Registers (PTDD, PTDPE, PTDSE, and PTDDD)
Port D includes eight pins shared between general-purpose I/O, TPM1, and TPM2. Port D pins used as
general-purpose I/O pins are controlled by the port D data (PTDD), data direction (PTDDD), pullup enable
(PTDPE), and slew rate control (PTDSE) registers.
If a TPM takes control of a port D pin, the corresponding PTDDD bit is ignored. When the TPM is in
output compare mode, the corresponding PTDSE can be used to provide slew rate on the pin. When the
TPM is in input capture mode, the corresponding PTDPE can be used, provided the corresponding
PTDDD bit is 0, to provide a pullup device on the pin.
Reads of PTDD will return the logic value of the corresponding pin, provided PTDDD is 0.
76543210
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PTDD7PTDD6PTDD5PTDD4PTDD3PTDD2PTDD1PTDD0
W
Reset00000000
Figure 6-21. Port D Data Register (PTDD)
Table 6-13. PTDD Field Descriptions
FieldDescription
7:0
PTDD[7:0]
R
W
Reset00000000
Port D Data Register Bits — For port D pins that are inputs, reads return the logic level on the pin. For port D
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For port D pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTDD to all 0s, but these 0s are not driven out the corresponding pins because reset also
configures all port pins as high-impedance inputs with pullups disabled.
76543210
PTDPE7PTDPE6PTDPE5PTDPE4PTDPE3PTDPE2PTDPE1PTDPE0
Figure 6-22. Pullup Enable for Port D (PTDPE)
Table 6-14. PTDPE Field Descriptions
FieldDescription
7:0
PTDPE[7:0]
Pullup Enable for Port D Bits — For port D pins that are inputs, these read/write control bits determine whether
internal pullup devices are enabled. For port D pins that are configured as outputs, these bits are ignored and
the internal pullup devices are disabled.
0 Internal pullup device disabled.
1 Internal pullup device enabled.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor91
Chapter 6 Parallel Input/Output
76543210
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PTDSE7PTDSE6PTDSE5PTDSE4PTDSE3PTDSE2PTDSE1PTDSE0
W
Reset00000000
Figure 6-23. Slew Rate Control Enable for Port D (PTDSE)
Table 6-15. PTDSE Field Descriptions
FieldDescription
7:0
PTDSE[7:0]
Slew Rate Control Enable for Port D Bits — For port D pins that are outputs, these read/write control bits
determine whether the slew rate controlled outputs are enabled. For port D pins that are configured as inputs,
these bits are ignored.
0 Slew rate control disabled.
1 Slew rate control enabled.
76543210
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PTDDD7PTDDD6PTDDD5PTDDD4PTDDD3PTDDD2PTDDD1PTDDD0
W
Reset00000000
Figure 6-24. Data Direction for Port D (PTDDD)
Table 6-16. PTDDD Field Descriptions
FieldDescription
7:0
PTDDD[7:0]
Data Direction for Port D Bits — These read/write bits control the direction of port D pins and what is read for
PTDD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for port D bit n and PTDD reads return the contents of PTDDn.
MC9S08GB60A Data Sheet, Rev. 1.00
92Freescale Semiconductor
Chapter 6 Parallel Input/Output
6.6.5Port E Registers (PTED, PTEPE, PTESE, and PTEDD)
Port E includes eight general-purpose I/O pins that share with the SCI1 and SPI modules. Port E pins used
as general-purpose I/O pins are controlled by the port E data (PTED), data direction (PTEDD), pullup
enable (PTEPE), and slew rate control (PTESE) registers.
If the SCI1 takes control of a port E pin, the corresponding PTEDD bit is ignored. PTESE can be used to
provide slew rate on the SCI1 transmit pin, TxD1. PTEPE can be used, provided the corresponding
PTEDD bit is 0, to provide a pullup device on the SCI1 receive pin, RxD1.
If the SPI takes control of a port E pin, the corresponding PTEDD bit is ignored. PTESE can be used to
provide slew rate on the SPI serial output pin (MOSI1 or MISO1) and serial clock pin (SPSCK1)
depending on the SPI operational mode. PTEPE can be used, provided the corresponding PTEDD bit is 0,
to provide a pullup device on the SPI serial input pins (MOSI1 or MISO1) and slave select pin (
depending on the SPI operational mode.
Reads of PTED will return the logic value of the corresponding pin, provided PTEDD is 0.
76543210
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PTED7PTED6PTED5PTED4PTED3PTED2PTED1PTED0
W
SS1)
Reset00000000
Figure 6-25. Port E Data Register (PTED)
Table 6-17. PTED Field Descriptions
FieldDescription
7:0
PTED[7:0]
Port E Data Register Bits — For port E pins that are inputs, reads return the logic level on the pin. For port E
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits in this register. For port E pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTED to all 0s, but these 0s are not driven out the corresponding pins because reset also configures
all port pins as high-impedance inputs with pullups disabled.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor93
Chapter 6 Parallel Input/Output
76543210
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PTEPE7PTEPE6PTEPE5PTEPE4PTEPE3PTEPE2PTEPE1PTEPE0
W
Reset00000000
Figure 6-26. Pullup Enable for Port E (PTEPE)
Table 6-18. PTEPE Field Descriptions
FieldDescription
7:0
PTEPE[7:0]
Pullup Enable for Port E Bits — For port E pins that are inputs, these read/write control bits determine whether
internal pullup devices are enabled. For port E pins that are configured as outputs, these bits are ignored and
the internal pullup devices are disabled.
0 Internal pullup device disabled.
1 Internal pullup device enabled.
76543210
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PTESE7PTESE6PTESE5PTESE4PTESE3PTESE2PTESE1PTESE0
W
Reset00000000
Figure 6-27. Slew Rate Control Enable for Port E (PTESE)
Table 6-19. PTESE Field Descriptions
FieldDescription
7:0
PTESE[7:0]
Slew Rate Control Enable for Port E Bits — For port E pins that are outputs, these read/write control bits
determine whether the slew rate controlled outputs are enabled. For port E pins that are configured as inputs,
these bits are ignored.
0 Slew rate control disabled.
1 Slew rate control enabled.
76543210
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PTEDD7PTEDD6PTEDD5PTEDD4PTEDD3PTEDD2PTEDD1PTEDD0
W
Reset00000000
Figure 6-28. Data Direction for Port E (PTEDD)
Table 6-20. PTEDD Field Descriptions
FieldDescription
7:0
PTEDD[7:0]
94Freescale Semiconductor
Data Direction for Port E Bits — These read/write bits control the direction of port E pins and what is read for
PTED reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for port E bit n and PTED reads return the contents of PTEDn.
MC9S08GB60A Data Sheet, Rev. 1.00
Chapter 6 Parallel Input/Output
6.6.6Port F Registers (PTFD, PTFPE, PTFSE, and PTFDD)
Port F includes eight general-purpose I/O pins that are not shared with any peripheral module. Port F pins
used as general-purpose I/O pins are controlled by the port F data (PTFD), data direction (PTFDD), pullup
enable (PTFPE), and slew rate control (PTFSE) registers.
76543210
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PTFD7PTFD6PTFD5PTFD4PTFD3PTFD2PTFD1PTFD0
W
Reset00000000
Figure 6-29. Port PTF Data Register (PTFD)
Table 6-21. PTFD Field Descriptions
FieldDescription
7:0
PTFD[7:0]
R
W
Reset00000000
Port PTF Data Register Bits — For port F pins that are inputs, reads return the logic level on the pin. For port
F pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For port F pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTFD to all 0s, but these 0s are not driven out the corresponding pins because reset also configures
all port pins as high-impedance inputs with pullups disabled.
76543210
PTFPE7PTFPE6PTFPE5PTFPE4PTFPE3PTFPE2PTFPE1PTFPE0
Figure 6-30. Pullup Enable for Port F (PTFPE)
Table 6-22. PTFPE Field Descriptions
FieldDescription
7:0
PTFPE[7:0]
Pullup Enable for Port F Bits — For port F pins that are inputs, these read/write control bits determine whether
internal pullup devices are enabled. For port F pins that are configured as outputs, these bits are ignored and
the internal pullup devices are disabled.
0 Internal pullup device disabled.
1 Internal pullup device enabled.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor95
Chapter 6 Parallel Input/Output
76543210
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PTFSE7PTFSE6PTFSE5PTFSE4PTFSE3PTFSE2PTFSE1PTFSE0
W
Reset00000000
Figure 6-31. Slew Rate Control Enable for Port F (PTFSE)
Table 6-23. PTFSE Field Descriptions
FieldDescription
7:0
PTFSE[7:0]
R
W
Reset00000000
Slew Rate Control Enable for Port F Bits — For port F pins that are outputs, these read/write control bits
determine whether the slew rate controlled outputs are enabled. For port F pins that are configured as inputs,
these bits are ignored.
0 Slew rate control disabled.
1 Slew rate control enabled.
76543210
PTFDD7PTFDD6PTFDD5PTFDD4PTFDD3PTFDD2PTFDD1PTFDD0
Figure 6-32. Data Direction for Port F (PTFDD)
Table 6-24. PTFDD Field Descriptions
FieldDescription
7:0
PTFDD[7:0]
Data Direction for Port F Bits — These read/write bits control the direction of port F pins and what is read for
PTFD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for port F bit n and PTFD reads return the contents of PTFDn.
6.6.7Port G Registers (PTGD, PTGPE, PTGSE, and PTGDD)
Port G includes eight general-purpose I/O pins that are shared with BKGD/MS function and the oscillator
or external clock pins. Port G pins used as general-purpose I/O pins are controlled by the port G data
(PTGD), data direction (PTGDD), pullup enable (PTGPE), and slew rate control (PTGSE) registers.
Port pin PTG0, while in reset, defaults to the BKGD/MS pin. After the MCU is out of reset, PTG0 can be
configured to be a general-purpose output pin. When BKGD/MS takes control of PTG0, the corresponding
PTGDD, PTGPE, and PTGPSE bits are ignored.
Port pins PTG1 and PTG2 can be configured to be oscillator or external clock pins. When the oscillator
takes control of a port G pin, the corresponding PTGD, PTGDD, PTGSE, and PTGPE bits are ignored.
Reads of PTGD will return the logic value of the corresponding pin, provided PTGDD is 0.
MC9S08GB60A Data Sheet, Rev. 1.00
96Freescale Semiconductor
Chapter 6 Parallel Input/Output
76543210
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PTGD7PTGD6PTGD5PTGD4PTGD3PTGD2PTGD1PTGD0
W
Reset00000000
Figure 6-33. Port PTG Data Register (PTGD)
Table 6-25. PTGD Field Descriptions
FieldDescription
7:0
PTGD[7:0]
Port PTG Data Register Bits — For port G pins that are inputs, reads return the logic level on the pin. For port
G pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For port G pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTGD to all 0s, but these 0s are not driven out the corresponding pins because reset also
configures all port pins as high-impedance inputs with pullups disabled.
76543210
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PTGPE7PTGPE6PTGPE5PTGPE4PTGPE3PTGPE2PTGPE1PTGPE0
W
Reset00000000
Figure 6-34. Pullup Enable for Port G (PTGPE)
Table 6-26. PTGPE Field Descriptions
FieldDescription
7:0
PTGPE[7:0]
Pullup Enable for Port G Bits — For port G pins that are inputs, these read/write control bits determine whether
internal pullup devices are enabled. For port G pins that are configured as outputs, these bits are ignored and
the internal pullup devices are disabled.
0 Internal pullup device disabled.
1 Internal pullup device enabled.
MC9S08GB60A Data Sheet, Rev. 1.00
Freescale Semiconductor97
Chapter 6 Parallel Input/Output
76543210
R
PTGSE7PTGSE6PTGSE5PTGSE4PTGSE3PTGSE2PTGSE1PTGSE0
W
Reset00000000
Figure 6-35. Slew Rate Control Enable for Port G (PTGSE)
Table 6-27. PTGSE Field Descriptions
FieldDescription
7:0
PTGSE[7:0]
Slew Rate Control Enable for Port G Bits — For port G pins that are outputs, these read/write control bits
determine whether the slew rate controlled outputs are enabled. For port G pins that are configured as inputs,
these bits are ignored.
0 Slew rate control disabled.
1 Slew rate control enabled.
76543210
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PTGDD7PTGDD6PTGDD5PTGDD4PTGDD3PTGDD2PTGDD1PTGDD0
W
Reset00000000
Figure 6-36. Data Direction for Port G (PTGDD)
Table 6-28. PTGDD Field Descriptions
FieldDescription
7:0
PTGDD[7:0]
Data Direction for Port G Bits — These read/write bits control the direction of port G pins and what is read for
PTGD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for port G bit n and PTGD reads return the contents of PTGDn.
MC9S08GB60A Data Sheet, Rev. 1.00
98Freescale Semiconductor
Chapter 7
Internal Clock Generator (S08ICGV2)
The MC9S08GBxxA/GTxxA microcontroller provides one internal clock generation (ICG) module to
create the system bus frequency. All functions described in this section are available on the
MC9S08GBxxA/GTxxA microcontroller. The EXTAL and XTAL pins share port G bits 2 and 1,
respectively. Analog supply lines V
DDA
and V
pins. Electrical parametric data for the ICG may be found in Appendix A, “Electrical Characteristics.”
are internally derived from the MCU’s VDD and V
SSA
SS
ICG
ICGERCLK
FFE
SYSTEM
CONTROL
LOGIC
RTI
TPM1TPM2IIC1SCI1SCI2SPI1
÷2
FIXED FREQ CLOCK (XCLK)
ICGOUT
ICGLCLK*
* ICGLCLK is the alternate BDC clock source for the MC9S08GBxxA/GTxxA.
÷2
CPU
BUSCLK
BDC
ATD1
ATD has min and max
frequency requirements. See
Chapter 1, “Device Overview” and
Appendix A, “Electrical Characteristics.
RAMFLASH
Figure 7-1. System Clock Distribution Diagram
NOTE
Freescale Semiconductor recommends that FLASH location $FFBE be
reserved to store a nonvolatile version of ICGTRM. This will allow
debugger and programmer vendors to perform a manual trim operation and
store the resultant ICGTRM value for users to access at a later time.
FLASH has frequency
requirements for program
and erase operation.
See Appendix A, “Electrical