NSC COP87L88RDV-XE, COP87L88RDN-XE Datasheet
COP87L88GD/RD Family
8-Bit CMOS OTP Microcontrollers with 16k or 32k
Memory and 8-Channel A/D with Prescaler
General Description
The COP87L88GD/RD OTP (One Time Programmable)
Family microcontrollers are highly integratet COP8
™
Feature core devices with 16k or 32k memory and advanced
features including anA/DConverter. These multi-chip CMOS
devices are suited for applications requiring a full featured
controller with an 8-bit A/D converter, and as pre-production
devices for a masked ROM design. Pin and software compatible 16k ROM versions are available (COP888GD), as
well as a range of COP8 software and hardware development tools.
Family features include an 8-bit memory mapped architecture, 10 MHz CKI (-XE=crystal oscillator) with 1µs instruction cycle, three multi-function 16-bit timer/counters,
MICROWIRE/PLUS
™
serial I/O, one 8-bit/8-channel A/D
converter with prescaler and both differential and single
ended modes, two power saving HALT/IDLE modes, MIWU,
idle timer, high current outputs, software selectable I/O options, WATCHDOG
™
timer and Clock Monitor, 2.7V to 5.5V
operation, program code security, and 44 pin package.
Devices included in this datasheet are:
Device Memory (bytes) RAM (bytes) I/O Pins Packages Temperature
COP87L88GD 16k EPROM 256 40 44 PLCC -40 to +85˚C
COP87L88RD 32k EPROM 256 40 44 PLCC -40 to +85˚C
Key Features
n 8-channel A/D converter with prescaler and both
differential and single ended modes
n Idle Timer with 5 selectable Wake-Up periods
n Three 16-bit timers, each with two 16-bit registers
supporting:
— Processor Independent PWM mode
— External Event counter mode
— Input Capture mode
n 16 or 32 kbytes on-board OTP EPROM with security
feature
n 256 bytes on-board RAM
Additional Peripheral Features
n Multi-Input Wakeup (MIWU) with optional interrupts (8)
n WATCHDOG and clock monitor logic
n MICROWIRE/PLUS serial I/O
I/O Features
n Memory mapped I/O
n Software selectable I/O options (TRI-STATE
®
Output,
Push-Pull Output, Weak Pull Up Input, High Impedance
Input)
n Schmitt trigger inputs on ports G and L
n Package:
— 44 PLCC with 40 I/O pins
CPU/Instruction Set Features
n 1 µs instruction cycle time
n Twelve multi-source vectored interrupts servicing
— External Interrupt
— Idle Timer T0
— Three Timers (each with 2 Interrupts)
— MICROWIRE/PLUS
— Multi-Input Wake Up
— Software Trap
— Default VIS (default interrupt)
n Versatile and easy to use instruction set
n 8-bit Stack Pointer (SP) – stack in RAM
n Two 8-bit Register Indirect Data Memory Pointers (B
and X)
Fully Static CMOS
n Two power saving modes: HALT and IDLE
n Single supply operation: 2.7V to 5.5V
n Temperature range: −40˚C to +85˚C
Development Support
n Emulation device for COP888GD
n Real time emulation and full program debug offered by
MetaLink Development System
TRI-STATE®is a registered trademark ofNational Semiconductor Corporation.
MICROWIRE/PLUS
™
, COP8™, MICROWIRE™and WATCHDOG™are trademarks of National Semiconductor Corporation.
iceMASTER
®
is a registered trademark of MetaLink Corporation.
September 1999
COP87L88GD/RD Family 8-Bit CMOS OTP Microcontrollers with 16k or 32k Memory and
8-Channel A/D with Prescaler
© 1999 National Semiconductor Corporation DS012526 www.national.com
Block Diagram
Connection Diagrams
DS012526-1
FIGURE 1. Block Diagram
Plastic Chip Carrier
DS012526-2
Note: -X Crystal Oscillator
-E Halt Mode Enabled
Top View
Order Number COP87L88RDV-XE,
or COP87L88GDV-XE
See NS Plastic Chip Package Number V44A
FIGURE 2. Connection Diagrams
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Connection Diagrams (Continued)
Pinouts for 40- and 44-Pin Packages
Port Type Alt. Fun Alt. Fun 44-Pin Package
L0 I/O MIWU 17
L1 I/O MIWU 18
L2 I/O MIWU 19
L3 I/O MIWU 20
L4 I/O MIWU T2A 25
L5 I/O MIWU T2B 26
L6 I/O MIWU T3A 27
L7 I/O MIWU T3B 28
G0 I/O INT 39
G1 WDOUT 40
G2 I/O T1B 41
G3 I/O T1A 42
G4 I/O SO 3
G5 I/O SK 4
G6 I SI 5
G7 I/CKO HALT Restart 6
D0 O 29
D1 O 30
D2 O 31
D3 O 32
D4 O 33
D5 O 34
D6 O 35
D7 O 36
I0 I ACH0 9
I1 I ACH1 10
I2 I ACH2 11
I3 I ACH3 12
I4 I ACH4 13
I5 I ACH5 14
I6 I ACH6 15
I7 I ACH7 16
C0 I/O 43
C1 I/O 44
C2 I/O 1
C3 I/O 2
C4 I/O 21
C5 I/O 22
C6 I/O 23
C7 I/O 24
V
CC
8
GND 37
CKI 7
RESET
38
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Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (V
CC
)7V
Voltage at Any Pin −0.3V to V
CC
+ 0.3V
Total Current into V
CC
Pin
(Source) 100 mA
Total Current out of GND Pin
(Sink) 110 mA
Storage Temperature Range −65˚C to +140˚C
Note 1:
Absolute maximum ratings indicate limits beyond which damage to
the device may occur. DC and AC electrical specifications are not ensured
when operating the device at absolute maximum ratings.
DC Electrical Characteristics
−40˚C ≤ TA≤ +85˚C unless otherwise specified
Parameter Conditions Min Typ Max Units
Operating Voltage 2.7 5.5 V
Power Supply Ripple (Note 3) Peak-to-Peak 0.1 V
CC
V
Supply Current (Note 4)
CKI=10 MHz V
CC
=
5.5V, t
c
=
1µs 20 mA
CKI=4 MHz V
CC
=
4.0V, t
c
=
2.5 µs 10 mA
HALT Current (Note 5) V
CC
=
5.5V, CKI=0 MHz 12 µA
V
CC
=
4.0V, CKI=0 MHz 10 µA
IDLE Current (Note 4)
CKI=10 MHz V
CC
=
5.5V, t
c
=
1 µs 1.2 mA
CKI=4 MHz V
CC
=
4.0V, t
c
=
2.5 µs 1 mA
Input Levels
RESET , CKI
Logic High 0.8 V
CC
V
Logic Low 0.2 V
CC
V
All Other Inputs (L0-L7, G0-G6, C0-C7, I0-I7)
Logic High 0.7 V
CC
V
Logic Low 0.2 V
CC
V
Hi-Z Input Leakage V
CC
=
5.5V −2 +2 µA
Input Pullup Current V
CC
=
5.5V, V
IN
=
0V −40 −250 µA
G and L Port Input Hysteresis (Note 9) 0.35 V
CC
V
Output Current Levels
D Outputs
Source V
CC
=
4.5V, V
OH
=
3.3V −0.4 mA
Sink (Note 6) V
CC
=
4.5V, V
OL
=
1V 10 mA
All Others
Source (Weak Pull-Up Mode) V
CC
=
4.5V, V
OH
=
2.7V −10 −100 µA
Source (Push-Pull Mode) V
CC
=
4.5V, V
OH
=
3.3V −0.4 mA
Sink (Push-Pull Mode) V
CC
=
4.5V, V
OL
=
0.4V 1.6 mA
TRI-STATE Leakage V
CC
=
5.5V −2 +2 µA
Allowable Sink/Source Current per Pin
D Outputs (Sink) 15 mA
All others 3mA
Maximum Input Current Room Temp
±
100 mA
without Latchup (Notes 7, 9)
RAM Retention Voltage, V
r
500 ns Rise 2 V
and Fall Time (min)
Input Capacitance 7pF
Load Capacitance on D2 1000 pF
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AC Electrical Characteristics
−40˚C ≤ TA≤ +85˚C unless otherwise specified
Parameter Conditions Min Typ Max Units
Instruction Cycle Time (t
c
)
Crystal, Resonator, 4.5V ≤ V
CC
≤ 5.5V 1.0 DC µs
R/C Oscillator 4.5V ≤ V
CC
≤ 5.5V 3.0 DC µs
CKI Clock Duty Cycle (Note 9) f
r
=
Max 40 60
%
Rise Time (Note 9) f
r
=
10 MHz Ext Clock 5 ns
Fall Time (Note 9) f
r
=
10 MHz Ext Clock 5 ns
Inputs
t
SETUP
4.5V ≤ VCC≤ 5.5V 200 ns
t
HOLD
4.5V ≤ VCC≤ 5.5V 60 ns
Output Propagation Delay (Note 8) R
L
=
2.2k, C
L
=
100 pF
t
PD1,tPD0
SO, SK 4.5V ≤ VCC≤ 5.5V 0.7 µs
All Others 4.5V ≤ V
CC
≤ 5.5V 1.0 µs
MICROWIRE
™
Setup Time (t
UWS
) (Note 9) 20 ns
MICROWIRE Hold Time (t
UWH
) (Note 9) 56 ns
MICROWIRE Output Propagation Delay (t
UPD
) 220 ns
Input Pulse Width (Note 9)
Interrupt Input High Time 1.0 t
c
Interrupt Input Low Time 1.0 t
c
Timer 1, 2, 3 Input High Time 1.0 t
c
Timer 1, 2, 3 Input Low Time 1.0 t
c
Reset Pulse Width 1.0 µs
Note 2: t
c
=
Instruction Cycle Time
Note 3: Maximum rate of voltage change must be
<
0.5 V/ms.
Note 4: Supply and IDLE currents are measured with CKI driven with a square wave Oscillator, CKO driven 180˚ out of phase with CKI, inputs connected to V
CC
and outputs driven low but not connected to a load.
Note 5: The HALT mode will stop CKI from oscillating in the RC and the Crystal configurations by bringing CKI high. Measurement of I
DD
HALTis done with device
neither sourcing nor sinking current; with L, C, G0, and G2–G5 programmed as low outputs and not driving a load; all outputs programmed low and not driving a load;
all inputs tied to V
CC
; clock monitor and comparator disabled. Parameter refers to HALT mode entered via setting bit 7 of the G Port data register. Part will pull up
CKI during HALT in crystal clock mode.
Note 6: The user must guarantee that D2 pin does not source more than 10 mA during RESET. If D2 sources more than 10 mA during reset, the device will go into
programming mode.
Note 7: Pins G6 and RESET are designed with a high voltage input network. These pins allow input voltages
>
VCCand the pins will have sink current to VCCwhen
biased at voltages>VCC(the pins do not have source current when biased at a voltage below VCC). The effective resistance to VCCis 750Ω (typical). These two
pins will not latch up. The voltage at the pins must be limited to
<
14V.WARNING: Voltages in excess of 14V will cause damage to the pins. This warning excludes
ESD transients.
Note 8: The output propagation delay is referenced to the end of the instruction cycle where the output change occurs.
Note 9: Parameter characterized but not tested.
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A/D Converter Specifications
V
CC
=
5V
±
10%,(VSS–0.050V) ≤ Any Input ≤ (VCC+ 0.050V)
Parameter Conditions Min Typ Max Units
Resolution 8 Bits
Absolute Accuracy
±
2 LSB
Non-Linearity Deviation from the Best Straight Line
±
1 LSB
Differential Non-Linearity
±
1 LSB
Common Mode Input Range (Note 12) GND V
CC
V
DC Common Mode Error
±
1/2 LSB
Off Channel Leakage Current 1 2 µA
On Channel Leakage Current 1 2 µA
A/D Clock Frequency (Note 11) 0.1 1.67 MHz
Converison Time (Note 10) 17 A/D Clock Cycles
Internal Reference Resistance 1µs
Tum-on Time (Note 13)
Note 10: Conversion Time includes 7 A/D clock cycles sample and hold time.
Note 11: See Prescaler description.
Note 12: For V
IN
(−)
>
=
V
IN
(+) the digital output code will be 0000 0000. Two on-chip diodes are tied to each analog input. The diodes will forward conduct for ana-
log input voltages below ground or above the V
CC
supply. Be careful, during testing at low VCClevels (4.5V), as high level analog inputs (5V) can cause this input
diode to conduct — especially at elevated temperatures, and cause errors for analog inputs near full-scale. The spec allows 50 mV forward bias of either diode. This
means that as long as the analog V
IN
does not exceed the supply voltage by more than 50 mV, the output code will be correct. To achieve an absolute 0 VDCto 5
V
DC
input voltage range will therefore require a minimum supply voltage of 4.950 VDCover temperature variations, initial tolerance and loading.
Note 13: Time or internal reference reistance to turn on and settle after coming out of HALT or IDLE mode.
DS012526-4
FIGURE 3. MICROWIRE/PLUS Timing
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Typical Performance Characteristics (−55˚C ≤ T
A
=
+125˚C)
DS012526-22 DS012526-23
DS012526-24 DS012526-25
DS012526-26
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Pin Descriptions
VCCand GND are the power supply pins. All VCCand GND
pins must be connected.
CKI is the clock input. This can come from an R/C generated
oscillator, or a crystal oscillator (in conjunction with CKO).
See Oscillator Description section.
RESET is the master reset input. See Reset Description section.
The device contains three bidirectional 8-bit I/O ports (C, G
and L), where each individual bit may be independently configured as an input (Schmitt Trigger inputs on ports Land G),
output or TRI-STATE under program control. Three data
memory address locations are allocated for each of these
I/O ports. Each I/O port has two associated 8-bit memory
mapped registers, the CONFIGURATION register and the
output DATAregister.A memory mapped address is also reserved for the input pins of each I/O port. (See the memory
map for the various addresses associated with the I/O ports.)
Figure 4
shows the I/O port configurations. The DATA and
CONFIGURATION registers allow for each port bit to be individually configured under software control as shown below:
CONFIGURATION DATA Port Set-Up
Register Register
0 0 Hi-Z Input
(TRI-STATE Output)
0 1 Input with Weak Pull-Up
1 0 Push-Pull Zero Output
1 1 Push-Pull One Output
PORT L is an 8-bit I/O port. All L-pins have Schmitt triggers
on the inputs.
Port L supports Multi-Input Wake Up on all eight pins. L4 and
L5 are used for the timer input functions T2A and T2B. L6
and L7 are used for the timer input functions T3A and T3B.
Port L has the following alternate features:
L7 MIWU or T3B
L6 MIWU or T3A
L5 MIWU or T2B
L4 MIWU or T2A
L3 MIWU
L2 MIWU
L1 MIWU
L0 MIWU
Port G is an 8-bit port with 5 I/O pins (G0, G2–G5), an input
pin (G6), and a dedicated output pin (G7). Pins G0 and
G2–G6 all have Schmitt Triggers on their inputs. Pin G1
serves as the dedicated WDOUT WATCHDOGoutput, while
pin G7 is either input or output depending on the oscillator
mask option selected. With the crystal oscillator option selected, G7 serves as the dedicated output pin for the CKO
clock output. With the single-pin R/C oscillator mask option
selected, G7 serves as a general purpose input pin but is
also used to bring the device out of HALTmode with a low to
high transition on G7. There are two registers associated
with the G Port, a data register and a configuration register.
Therefore, each of the 5 I/O bits (G0, G2–G5) can be individually configured under software control.
Since G6 is an input only pin and G7 is the dedicated CKO
clock output pin (crystal clock option) or general purpose input (R/C clock option), the associated bits in the data and
configuration registers for G6 and G7 are used for special
purpose functions as outlined on the next page. Reading the
G6 and G7 data bits will return zeros.
Note that the chip will be placed in the HALTmode by writing
a “1” to bit 7 of the Port G Data Register. Similarly the chip
will be placed in the IDLE mode by writing a “1” to bit 6 of the
Port G Data Register.
Writing a “1” to bit 6 of the Port G Configuration Register enables the MICROWIRE/PLUS to operate with the alternate
phase of the SK clock. The G7 configuration bit, if set high,
enables the clock start up delay after HALT when the R/C
clock configuration is used.
Config Reg. Data Reg.
G7 CLKDLY HALT
G6 Alternate SK IDLE
Port G has the following alternate features:
G6 SI (MICROWIRE Serial Data Input)
G5 SK (MICROWIRE Serial Clock)
G4 SO (MICROWIRE Serial Data Output)
G3 T1A (Timer T1 I/O)
G2 T1B (Timer T1 Capture Input)
G0 INTR (External Interrupt Input)
Port G has the following dedicated functions:
G7 CKO Oscillator dedicated output or general purpose
input
G1 WDOUT WATCHDOG and/or Clock Monitor dedi-
cated output
Port C is an 8-bit I/O port. The 40-pin device does not have
a full complement of Port C pins. The unavailable pins are
not terminated. A read operation for these unterminated pins
will return unpredicatable values.
Port I is an 8-bit Hi-Z input port, and also provides theanalog
inputs to the A/D converter. The 28-pin device does not have
a full complement of Port I pins. The unavailable pins are not
terminated (i.e. they are floating). A read operation from
these unterminated pins will return unpredictable values.
The user should ensure that the software takes this into account by either masking out these inputs, or else restricting
the accesses to bit operations only. If unterminated, Port I
pins will draw power only when addressed.
Port D is an 8-bit output port that is preset high whenRESET
goes low. The user can tie two or more D port outputs (except D2) together in order to get a higher drive.
DS012526-5
FIGURE 4. I/O Port Configurations
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Pin Descriptions (Continued)
Note: Care must be exercised with the D2 pin operation. At RESET, the ex-
ternal loads on this pin must ensure that the output voltages stay
above 0.8 V
CC
to prevent the chip from entering special modes. Also
keep the external loading on D2 to
<
1000 pF.
Functional Description
The architecture of the device is modified Harvard architecture. With the Harvard architecture, the control store program memory (ROM) is separated from the data store
memory (RAM). Both ROM and RAM have their own separate addressing space with separate address buses. The architecture, though based on Harvard architecture, permits
transfer of data from ROM to RAM.
CPU REGISTERS
The CPU can do an 8-bit addition, subtraction, logical orshift
operation in one instruction (t
c
) cycle time.
There are six CPU registers:
A is the 8-bit Accumulator Register
PC is the 15-bit Program Counter Register
PU is the upper 7 bits of the program counter (PC)
PL is the lower 8 bits of the program counter (PC)
B is an 8-bit RAM address pointer, which can be optionally
post auto incremented or decremented.
X is an 8-bit alternate RAM address pointer, which can be
optionally post auto incremented or decremented.
SP is the 8-bit stack pointer, which points to the subroutine/
interrupt stack (in RAM). The SP is initialized to RAM address 06F with reset.
S is the 8-bit Data SegmentAddress Register used to extend
the lower half of the address range (00 to 7F) into 256 data
segments of 128 bytes each.
All the CPU registers are memory mapped with the exception of the Accumulator (A) and the Program Counter (PC).
PROGRAM MEMORY
The program memory consists of 16 or 32 kbytes of OTP
EPROM. These bytes may hold program instructions or constant data (data tables for the LAID instruction, jump vectors
for the JID instruction, and interrupt vectors for the VIS instruction). The program memory is addressed by the 15-bit
program counter (PC). All interrupts in the devices vector to
program memory location 0FF Hex.
The device can be configured to inhibit external reads of the
program memory. This is done by programming the Security
Byte.
SECURITY FEATURE
The program memory array has an associated Security Byte
that is located outside of the program address range. This
byte can be addressed only from programming mode by a
programmer tool.
Security is an optional feature and can only be assertedafter
the memory array has been programmed and verified. A secured part will read all 00(hex) by a programmer. The part
will fail Blank Check and will fail Verify operations. A Read
operation will fill the programmer’s memory with 00(hex).
The Security Byte itself is always readable with a value of
00(hex) if unsecure and FF(hex) if secure.
DATA MEMORY
The data memory address space includes the on-chip RAM
and data registers, the I/O registers (Configuration, Data and
Pin), the control registers, the MICROWIRE/PLUS SIO shift
register, and the various registers, and counters associated
with the timers (with the exception of the IDLE timer). Data
memory is addressed directly by the instruction or indirectly
by the B, X, SP pointers and S register.
The data memory consists of 256 bytes of RAM. Sixteen
bytes of RAM are mapped as “registers” at addresses 0F0 to
0FF Hex. These registers can be loaded immediately, and
also decremented and tested with the DRSZ (decrement
register and skip if zero) instruction. The memory pointer
registers X, SP,B and S are memory mapped into this space
at address locations 0FC to 0FF Hex respectively, with the
other registers being available for general usage.
The instruction set permits any bit in memory to be set, reset
or tested. All I/O and registers (except A and PC) are
memory mapped; therefore, I/O bits and register bits can be
directly and individually set, reset and tested. The accumulator (A) bits can also be directly and individually tested.
Note: RAM contents are undefined upon power-up.
Data Memory Segment RAM
Extension
Data memory address 0FF is used as a memory mapped location for the Data Segment Address Register (S).
The data store memory is either addressed directly by a
single byte address within the instruction, or indirectly relative to the reference of the B, X, or SP pointers (each contains a single-byte address).This single-byte address allows
an addressing range of 256 locations from 00 to FF hex. The
upper bit of this single-byte address divides the data store
memory into two separate sections as outlined previously.
With the exception of the RAM register memory from address locations 00F0 to 00FF, all RAM memory is memory
mapped with the upper bit of the single-byte address being
equal to zero. This allows the upper bit of the single-byte address to determine whether or not the base address range
(from 0000 to 00FF) is extended. If this upper bit equals one
(representing address range 0080 to 00FF), then address
extension does not take place. Alternatively, if this upper bit
equals zero, then the data segment extension register S is
used to extend the base address range (from 0000 to 007F)
from XX00 to XX7F, where XX represents the 8 bits from the
S register. Thus the 128-byte data segment extensions are
located from addresses 0100 to 017F for data segment 1,
0200 to 027F for data segment 2, etc., up to FF00 to FF7F
for data segment 255. The base address range from 0000 to
007F represents data segment 0.
Figure 5
illustrates how the S register data memory extension is used in extending the lower half of the base address
range (00 to 7F hex) into 256 data segments of 128 bytes
each, with a total addressing range of 32 kbytes from XX00
to XX7F. This organization allows a total of 256 data segments of 128 bytes each with an additional upper base segment of 128 bytes. Furthermore, all addressing modes are
available for all data segments. The S register must be
changed under program control to move from one data segment (128 bytes) to another. However, the upper base segment (containing the 16 memory registers, I/O registers,
control registers, etc.) is always available regardless of the
contents of the S register, since the upper base segment
(address range 0080 to 00FF) is independent of data segment extension.
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Data Memory Segment RAM
Extension
(Continued)
The instructions that utilize the stack pointer (SP) always reference the stack as part of the base segment (Segment 0),
regardless of the contents of the S register. The S register is
not changed by these instructions. Consequently, the stack
(used with subroutine linkage and interrupts) is always located in the base segment. The stack pointer will be initialized to point at data memory location 006F as a result of
reset.
The 128 bytes of RAM contained in the base segment are
split between the lower and upper base segments. The first
112bytes of RAM are resident from address 0000 to 006F in
the lower base segment, while the remaining 16 bytes of
RAM represent the 16 data memory registers located at addresses 00F0 to 00FF of the upper base segment. No RAM
is located at the upper sixteen addresses (0070 to 007F) of
the lower base segment.
Additional RAM beyond these initial 128 bytes, however, will
always be memory mapped in groups of 128 bytes (or less)
at the data segment address extensions (XX00 to XX7F) of
the lower base segment. The additional 128 bytes of RAM
are memory mapped at address locations 0100 to 017F hex.
Reset
The RESET input when pulled low initializes the microcontroller. Initialization will occur whenever the RESET input is
pulled low. Upon initialization, the data and configuration
registers for ports L, G and C are cleared, resulting in these
Ports being initialized to the TRI-STATE mode. Pin G1 of the
G Port is an exception (as noted below) since pin G1 is dedicated as the WATCHDOGand/or Clock Monitor error output
pin. Port D is set high. The PC, PSW, ICNTRL, CNTRL,
T2CNTRL and T3CNTRL control registers are cleared. The
Comparator Select Register is cleared. The S register is initialized to zero. The Multi-Input Wakeupregisters WKEN and
WKEDG are cleared. Wakeup register WKPND is unknown.
The stack pointer, SP, is initialized to 6F hex.
The device comes out of reset with both the WATCHDOG
logic and the Clock Monitor detector armed, with the
WATCHDOG service window bits set and the Clock Monitor
bit set. The WATCHDOG and Clock Monitor circuits are inhibited during reset. The WATCHDOG service window bits
being initialized high default to the maximum WATCHDOG
service window of 64k t
C
clock cycles. The Clock Monitor bit
being initialized high will cause a Clock Monitor error following reset if the clock has not reached the minimum specified
frequency at the termination of reset. A Clock Monitor error
will cause an active low error output on pin G1. This error
output will continue until 16 t
C
–32 tCclock cycles following
the clock frequency reaching the minimum specified value,
at which time the G1 output will enter the TRI-STATE mode.
The external RC network shown in
Figure 6
should be used
to ensure that the RESET pin is held low until the powersupply to the chip stabilizes.
Oscillator Circuits
The chip can be driven by a clock input on the CKI input pin
which can be between DC and 10 MHz. The CKO output
clock is on pin G7 (crystal configuration). The CKI input frequency is divided down by 10 to produce the instruction
cycle clock (1/t
c
).
Note: External clocks with frequencies above about 4 MHz require the user
to drive the CKO (G7) pin with a signal 180 degrees out of phase with
CKI.
Figure 7
shows the Crystal and R/C oscillator diagrams.
CRYSTAL OSCILLATOR
CKI and CKO can be connected to make a closed loop crystal (or resonator) controlled oscillator.
Table 1
shows the component values required for various
standard crystal values.
R/C OSCILLATOR
By selecting CKI as a single pin oscillator input, a single pin
R/C oscillator circuit can be connected to it. CKO is available
as a general purpose input, and/or HALT restart input.
Note: Use of the R/C oscillator option will result in higher electromagnetic
emissions.
Table 2
shows the variation in the oscillator frequencies as
functions of the component (R and C) values.
DS012526-6
*
Reads as all ones.
FIGURE 5. RAM Organization
DS012526-7
RC>5 x Power Supply Rise Time
FIGURE 6. Recommended Reset Circuit
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Oscillator Circuits (Continued)
TABLE 1. Crystal Oscillator Configuration, T
A
=
25˚C
R1 R2 C1 C2 CKI Freq Conditions
(kΩ)(MΩ) (pF) (pF) (MHz)
0 1 30 30–36 10 V
CC
=
5V
0 1 30 30–36 4 V
CC
=
5V
0 1 200 100–150 0.455 V
CC
=
5V
TABLE 2. RC Oscillator Configuration, T
A
=
25˚C
R C CKI Freq Instr. Cycle Conditions
(kΩ) (pF) (MHz) (µs)
3.3 82 2.2 to 2.7 3.7 to 4.6 V
CC
=
5V
5.6 100 1.1 to 1.3 7.4 to 9.0 V
CC
=
5V
6.8 100 0.9 to 1.1 8.8 to 10.8 V
CC
=
5V
Note 14: 3k ≤ R ≤ 200k
50 pF ≤ C ≤ 200 pF
CONTROL REGISTERS
CNTRL Register (Address X'00EE)
T1C3 T1C2 T1C1 T1C0 MSEL IEDG SL1 SL0
Bit 7 Bit 0
The Timer1 (T1) and MICROWIRE/PLUS control register
contains the following bits:
T1C3 Timer T1 mode control bit
T1C2 Timer T1 mode control bit
T1C1 Timer T1 mode control bit
T1C0 Timer T1 Start/Stop control in timer
modes 1 and 2, T1 Underflow Interrupt
Pending Flag in timer mode 3
MSEL Selects G5 and G4 as MICROWIRE/PLUS
signals SK and SO respectively
IEDG External interrupt edge polarity select
(0 = Rising edge, 1 = Falling edge)
SL1 & SL0 Select the MICROWIRE/PLUS clock divide
by (00 = 2, 01 = 4, 1x = 8)
PSW Register (Address X'00EF)
HC C T1PNDA T1ENA EXPND BUSY EXEN GIE
Bit 7 Bit 0
The PSW register contains the following select bits:
HC Half Carry Flag
C Carry Flag
T1PNDA Timer T1 Interrupt Pending Flag (Autoreload
RA in mode 1, T1 Underflow in Mode 2, T1A
capture edge in mode 3)
T1ENA Timer T1 Interrupt Enable for Timer Underflow
or T1A Input capture edge
EXPND External interrupt pending
BUSY MICROWIRE/PLUS busy shifting flag
EXEN Enable external interrupt
GIE Global interrupt enable (enables interrupts)
The Half-Carry flag is also affected by all the instructions that
affect the Carry flag. The SC (Set Carry) and R/C (Reset
Carry) instructions will respectively set or clear both the carry
flags. In addition to the SC and R/C instructions, ADC,
SUBC, RRC and RLC instructions affect the Carry and Half
Carry flags.
ICNTRL Register (Address X'00E8)
Reserved LPEN T0PND T0EN µWPND µWEN T1PNDB T1ENB
Bit 7 Bit 0
The ICNTRL register contains the following bits:
Reserved This bit is reserved and should to zero
LPEN L Port Interrupt Enable (Multi-Input Wakeup/
Interrupt)
T0PND Timer T0 Interrupt pending
T0EN Timer T0 Interrupt Enable (Bit 12 toggle)
µWPND MICROWIRE/PLUS interrupt pending
µWEN Enable MICROWIRE/PLUS interrupt
T1PNDB Timer T1 Interrupt Pending Flag for T1B cap-
ture edge
T1ENB Timer T1 Interrupt Enable for T1B Input cap-
ture edge
T2CNTRL Register (Address X'00C6)
T2C3 T2C2 T2C1 T2C0 T2PNDA T2ENA T2PNDB T2ENB
Bit 7 Bit 0
The T2CNTRL control register contains the following bits:
T2C3 Timer T2 mode control bit
T2C2 Timer T2 mode control bit
T2C1 Timer T2 mode control bit
T2C0 Timer T2 Start/Stop control in timer
modes 1 and 2, T2 Underflow Interrupt Pend-
ing Flag in timer mode 3
T2PNDA Timer T2 Interrupt Pending Flag (Autoreload
RA in mode 1, T2 Underflow in mode 2, T2A
capture edge in mode 3)
T2ENA Timer T2 Interrupt Enable for Timer Underflow
or T2A Input capture edge
T2PNDB Timer T2 Interrupt Pending Flag for T2B cap-
ture edge
DS012526-8
DS012526-9
FIGURE 7. Crystal and R/C Oscillator Diagrams
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CONTROL REGISTERS (Continued)
T2ENB Timer T2 Interrupt Enable for Timer Underflow
or T2B Input capture edge
T3CNTRL Register (Address X'00B6)
T3C3 T3C2 T3C1 T3C0 T3PNDA T3ENA T3PNDB T3ENB
Bit 7 Bit 0
The T3CNTRL control register contains the following bits:
T3C3 Timer T3 mode control bit
T3C2 Timer T3 mode control bit
T3C1 Timer T3 mode control bit
T3C0 Timer T3 Start/Stop control in timer
modes 1 and 2, T3 Underflow Interrupt Pending Flag in timer mode 3
T3PNDA Timer T3 Interrupt Pending Flag (Autoreload
RA in mode 1, T3 Underflow in mode 2, T3A
capture edge in mode 3)
T3ENA Timer T3 Interrupt Enable for Timer Underflow
or T3A Input capture edge
T3PNDB Timer T3 Interrupt Pending Flag for T3B cap-
ture edge
T3ENB Timer T3 Interrupt Enable for Timer Underflow
or T3B Input capture edge
Timers
The device contains a very versatile set of timers (T0, T1,
T2, T3). All timers and associated autoreload/capture registers power up containing random data.
TIMER T0 (IDLE TIMER)
The device supports applications that require maintaining
real time and low power with the IDLE mode. This IDLE
mode support is furnished by the IDLE timer T0, which is a
16-bit timer. The Timer T0 runs continuously at the fixed rate
of the instruction cycle clock, t
c
. The user cannot read or
write to the IDLE Timer T0, which is a count down timer.
The Timer T0 supports the following functions:
j
Exit out of the Idle Mode (See Idle Mode description)
j
WATCHDOG logic (See WATCHDOG description)
j
Start up delay out of the HALT mode
Figure 8
is a functional block diagram showing the structure
of the IDLE Timer and its associated interrupt logic.
Bits 11 through 15 of the ITMR register can be selected for
triggering the IDLE Timer interrupt. Each time the selected
bit underflows (every 4k, 8k, 16k, 32k or 64k instruction
cycles), the IDLE Timer interrupt pending bit T0PND is set,
thus generating an interrupt (if enabled), and bit 6 of the Port
G data register is reset, thus causing an exit from the IDLE
mode if the device is in that mode.
In order for an interrupt to be generated, the IDLE Timer interrupt enable bit T0EN must be set, and the GIE (Global Interrupt Enable) bit must also be set. The T0PND flag and
T0EN bit are bits 5 and 4 of the ICNTRL register, respectively.The interrupt can be used for any purpose. Typically, it
is used to perform a task upon exit from the IDLE mode. For
more information on the IDLE mode, refer to the PowerSave
Modes section.
The Idle Timer period is selected by bits 0–2 of the ITMR
register Bits 3–7 of the ITMR Register are reserved and
should not be used as software flags.
TABLE 3. Idle Timer Window Length
ITSEL2 ITSEL1 ITSEL0 Idle Timer Period
(Instruction Cycles)
0 0 0 4,096
0 0 1 8,192
0 1 0 16,384
0 1 1 32,768
1 X X 65,536
The ITMR is cleared on Reset and the Idle Timer period is reset to 4,096 instruction cycles.
ITMR Register (Address X’0xCF)
Reserved ITSEL2 ITSEL1 ITSEL0
Bit 7 Bit 0
Any time the IDLE Timer period is changed there is the possibility of generating a spurious IDLE Timer interrupt by setting the T0PND bit. The user is advised to disable IDLE
Timer interrupts prior to changing the value of the ITSEL bits
of the ITMR Register and then clear the T0PND bit before attempting to synchronize operation to the IDLE Timer.
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