NSC COPBC885WM, COPBC884WM, COPBC685WM, COPBC684WM Datasheet

COP884BC/COP885BC 8-Bit CMOS ROM Based Microcontrollers with 2k Memory, Comparators, and CAN Interface

General Description

The COP884BC ROM based microcontrollers are highly integrated COP8

™

Feature core devices with 2k memory and advanced features including a CAN 2.0B (passive) interface and two Analog comparators. These single-chip CMOS devices are suited for applications requiring a full featured controller with a CAN interface, low EMI, and an 8-bit 39 kHz PWM timer. COP87L84BC devices are pin and software compatible 16k OTP (One Time Programmable) versions for pre-production, and for use with a range of COP8 software and hardware development tools.

Features include an 8-bit memory mapped architecture, 10 MHz CKI (crystal osc) with 1µs instruction cycle, one multifunction 16-bit timer/counter, 8-bit 39 kHz PWM timer with 2 outputs, CAN 2.0B (passive) interface, MICROWIRE/ PLUS

™

serial I/O, two Analog comparators, two power saving HALT/IDLEmodes,idletimer, MIWU, software selectable I/O options, Power on Reset, low EMI 4.5V to 5.5V operation, and 20/28 pin packages.

Note: A companion device with CAN interface, more I/O and memory,A/D, and USART is the COP888EB.

Devices included in this datasheet are:

Device Memory (bytes) RAM (bytes) I/O Pins Packages Temperature

COP684BC 2k ROM 64 18 28 SOIC -55 to +125˚C COP884BC 2k ROM 64 18 28 SOIC -40 to +85˚C COP685BC 2k ROM 64 10 20 SOIC -55 to +125˚C COP885BC 2k ROM 64 10 20 SOIC -40 to +85˚C

Key Features

n CAN 2.0B (passive) Interface n Power On Reset (selectable) n One 16-bit timer, with two 16-bit registers supporting:

— Processor Independent PWM mode — External Event counter mode — Input Capture mode

n High speed, constant resolution 8-bit PWM/frequency

monitor timer with 2 output pins

n 2048 bytes on-board ROM n 64 bytes on-board RAM

Additional Peripheral Features

n Idle Timer n Multi-Input Wake Up (MIWU) with optional interrupts (7) n Two analog comparators 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 Packages: 28 SO with 18 I/O pins and 20 SO with 10

I/O pins

CPU/Instruction Set Features

n 1 µs instruction cycle time n Eleven multi-source vectored interrupts servicing

— External Interrupt — Idle Timer T0 — Timer T1 (with 2 Interrupts) — MICROWIRE/PLUS — Multi-Input Wake Up — Software Trap — PWM Timer — CAN Interface (with 3 interrupts)

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 Low current drain (typically

1 µA)

n Single supply operation: 4.5V–5.5V n Temperature ranges: −40˚C to +85˚C, −55˚C to +125˚C

Development Support

n Emulation and OTP devices n Real time emulation and full program debug offered by

MetaLink Development Systems

COP8™, and MICROWIRE/PLUS™are trademarks of National Semiconductor Corporation. TRI-STATE

is a registered trademark of National Semiconductor Corporation.

iceMASTER

is a registered trademark of MetaLink Corporation.

September 1999

COP884BC/COP885BC 8-Bit CMOS ROM Based Microcontrollers with 2k Memory, Comparators,

and CAN Interface

Block Diagram

DS012067-1

FIGURE 1. Block Diagram

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Connection Diagrams

Pinouts for 28-SO Package

Port

Type Alt. Function

20-Pin 28-Pin

Pin SO SO

G0 I/O INTR 17 25 G1 I/O 18 26 G2 I/O T1B 19 27 G3 I/O T1A 20 28 G4 I/O SO 1 1 G5 I/O SK 2 2 G6 I SI 3 3 G7 I CKO 4 4

L0 I/O CMP1IN+/MIWU 7 L1 I/O CMP1IN−/MIWU 8 L2 I/O CMP10UT/MIWU 9 L3 I/O CMP2IN−/MIWU 10 L4 I/O CMP2IN+/MIWU 7 11 L5 I/O CMP2IN−/PWM1/MIWU 8 12 L6 I/O CMP2OUT/PWM0/

CAPTIN/MIWU

D0 O 19 D1 O 20 D2 O 21 D3 O 22

CAN V

REF

14 18 CAN Tx0 O 11 15 CAN Tx1 O 10 14 CAN Rx0 I MIWU (Note 1) 13 17 CAN Rx1 I MIWU 12 16

GND 15 23

CKI I 5 5

RESET

I1624

Note 1: The MIWU function for the CAN interface is internal (see CAN interface block diagram)

DS012067-2

Top View

Order Number COP884BC-xxx/WM or

COP684BC-xxx/WM

See NS Package Number M28B

DS012067-76

Top View

Order Number COP885BC-xxx/WM or

COP685BC-xxx/WM

See NS Package Number M20B

FIGURE 2. Connection Diagrams

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Absolute Maximum Ratings (Note 2)

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.

Supply Voltage (V

)6V

Voltage at Any Pin −0.3V to V

+0.3V

Total Current into V

Pin (Source) 90 mA Total Current out of GND Pin (Sink) 100 mA Storage Temperature Range −65˚C to +150˚C

Note 2: 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 COP884BC:

−40˚C ≤ TA≤ +85˚C

Parameter Conditions Min Typ Max Units

Operating Voltage 4.5 5.5 V Power Supply Ripple (Note 3) Peak-to-Peak 0.1 V

V Supply Current CKI = 10 MHz (Note 4) V

= 5.5V, tc=1µs 15 mA

HALT Current (Notes 5, 6) V

= 5.5V, CKI=0MHz

Power-On Reset Enabled

300 480 µA

Power-On Reset Disabled

250 380 µA IDLE Current (Note 6) CKI = 10 MHz V

= 5.5V, tc= 1 µs 5.5 mA

Input Levels (V

IH,VIL

)

Reset, CKI

Logic High 0.8 V

Logic Low 0.2 V

All Other Inputs

Logic High 0.7 V

Logic Low 0.2 V

Hi-Z Input Leakage V

= 5.5V

2µA

Input Pull-up Current V

= 5.5V, VIN= 0V −40 −250 µA

G and L Port Input Hysteresis (Notes 9, 10) 0.05 V

Output Current Levels D Outputs

Source V

= 4.5V, VOH= 3.3V −0.4 mA

Sink V

= 4.5V, VOL= 1.0V 10 mA

Comparator Output (L2, L6)

Source (Push-Pull) V

= 4.5V, VOH= 3.3V −1.6 mA

Sink (Push-Pull) V

= 4.5V, VOL= 0.4V 1.6 mA

CAN Transmitter Outputs

Source (Tx1) V

= 4.5V, VOH=VCC− 0.1V −1.5 mA

= 4.5V, VOH=VCC− 0.6V −10 mA

Sink (Tx0) V

= 4.5V, VOL= 0.1V 1.5 mA

= 4.5V, VOL= 0.6V 10 mA

All Others

Source (Weak Pull-Up) V

= 4.5V, VOH= 2.7V −10 −110 µA

Source (Push-Pull) V

= 4.5V, VOH= 3.3V −0.4 mA

Sink (Push-Pull) V

= 4.5V, VOL= 0.4V 1.6 mA

TRl-STATE Leakage V

= 5.5V

2.0 µA

Allowable Sink/Source Current per Pin

D Outputs (Sink) 15 mA Tx0 (Sink) (Note 10) 30 mA Tx1 (Source) (Note 10)

All Other

mA mA

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DC Electrical Characteristics COP884BC: (Continued)

−40˚C ≤ TA≤ +85˚C

Parameter Conditions Min Typ Max Units

Maximum Input Current without Latchup (Notes 8, 10) Room Temp

100 mA

RAM Retention Voltage, V

(Note 9) 500 ns Rise and Fall Time 2.0 V Input Capacitance (Note 10) 7 pF Load Capacitance on D2 1000 pF

Note 3: Maximum rate of voltage change must be less than 0.5 V/ms Note 4: Supply current is measured after running 2000 cycles with a square wave CKI input, CKO open, inputs at V

or GND, and outputs open.

Note 5: The HALTmode will stop CKI from oscillating in the Crystal configurations. Halt test conditions: All inputs tiedto V

; L, and G port I/Os configured as outputs and programmed low; D outputs programmed low. 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: HALT and IDLE current specifications assume CAN block and comparators are disabled.

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Absolute Maximum Ratings (Note 7)

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.

Supply Voltage (V

)7V

Voltage at Any Pin −0.3V to V

+0.3V

Total Current into V

Pin (Source) 100 mA Total Current out of GND Pin (Sink) 110 mA Storage Temperature Range −65˚C to +150˚C

Note 7: 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 COP684BC:

−55˚C ≤ TA≤ +125˚C

Parameter Conditions Min Typ Max Units

Operating Voltage 4.5 5.5 V Power Supply Ripple (Note 3) Peak-to-Peak 0.1 V

V Supply Current CKI = 10 MHz (Note 4) V

= 5.5V, tc=1µs 15 mA

HALT Current (Notes 5, 6) V

= 5.5V, CKI=0MHz

Power-On Reset Enabled

300 480 µA

Power-On Reset Disabled

250 380 µA IDLE Current (Note 6) CKI = 10 MHz V

= 5.5V, tc= 1 µs 5.5 mA

Input Levels (V

IH,VIL

)

Reset, CKI

Logic High 0.8 V

Logic Low 0.2 V

All Other Inputs

Logic High 0.7 V

Logic Low 0.2 V

Hi-Z Input Leakage V

= 5.5V

5µA

Input Pull-up Current V

= 5.5V, VIN= 0V −35 −250 µA

G and L Port Input Hysteresis (Note 9) 0.05 V

Output Current Levels D Outputs

Source V

= 4.5V, VOH= 3.3V −0.4 mA

Sink V

= 4.5V, VOL= 1.0V 9.0 mA

Comparator Output (L2, L6)

Source (Push-Pull) V

= 4.5V, VOH= 3.3V −1.6 mA

Sink (Push-Pull) V

= 4.5V, VOL= 0.4V 1.6 mA

CAN Transmitter Outputs

Source (Tx1) V

= 4.5V, VOH=VCC− 0.1V −1.5 mA

= 4.5V, VOH=VCC− 0.6V −10 mA

Sink (Tx0) V

= 4.5V, VOL= 0.1V 1.5 mA

= 4.5V, VOL= 0.6V 10 mA

All Others

Source (Weak Pull-Up) V

= 4.5V, VOH= 2.7V −9.0 −100 µA

Source (Push-Pull) V

= 4.5V, VOH= 3.3V −0.4 mA

Sink (Push-Pull) V

= 4.5V, VOL= 0.4V 1.4 mA

TRl-STATE Leakage V

= 5.5V

5.0 µA

Allowable Sink/Source Current per Pin

D Outputs (Sink) 12 mA Tx0 (Sink) (Note 10) 30 mA Tx1 (Source) (Note 10)

All Other

2.5

mA mA

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DC Electrical Characteristics COP684BC: (Continued)

−55˚C ≤ TA≤ +125˚C

Parameter Conditions Min Typ Max Units

Maximum Input Current without Latchup (Notes 8, 10) Room Temp

100 mA

RAM Retention Voltage, V

(Note 9) 500 ns Rise and Fall Time 2.0 V Input Capacitance (Note 10) 7 pF Load Capacitance on D2 1000 pF

Note 8: Pins G6 and RESET are designed with a high voltage input network. These pins allow input voltages greater than VCCand the pins will have sink current to VCCwhen biased at voltages greater than 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 less than 14V.

Note 9: Condition and parameter valid only for part in HALT mode. Note 10: Parameter characterized but not tested.

AC Electrical Characteristics COP684BC and COP884BC:

−55˚C ≤ TA≤ +125˚C

Parameter Conditions Min Typ Max Units

Instruction Cycle Time (t

)

Crystal/Resonator V

≥ 4.5V 1.0 DC µs

Inputs

SETUP

VCC≥ 4.5V 200 ns

HOLD

VCC≥ 4.5V 60 ns

PWM Capture Input

SETUP

VCC≥ 4.5V 30 ns

HOLD

VCC≥ 4.5V 70 ns Output Propagation Delay (t

PD1,tPD0

) (Note 12) CL= 100 pF, RL= 2.2 kΩ

SK, SO V

≥ 4.5V 0.7 µs

PWM Outputs V

≥ 4.5V 75 ns

All Others V

≥ 4.5V 1 µs

MICROWIRE

Setup Time (t

UWS

) (Note 13) 20 ns

Hold Time (t

UWH

) (Note 13) 56 ns

Output Prop Delay (t

UPD

) 220 ns

Input Pulse Width (Note 14)

Interrupt High Time 1 t

Interrupt Low Time 1 t

Timer 1,2 High Time 1 t

Timer 1,2 Low Time 1 t

Reset Pulse Width (Note 13) 1.0 µs Power Supply Rise Time for Proper 50 µs 256*t

Operation of On-Chip RESET

Note 11: For device testing purposes of all AC parameters, VOHwill be tested at 0.5*VCC. Note 12: The output propagation delay is referenced to the end of the instruction cycle where the output change occurs. Note 13: Parameter not tested. Note 14: t

= Instruction Cycle Time.

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On-Chip Voltage Reference:

−55˚C ≤ TA≤ +125˚C

Parameter Conditions Min Max Units

Reference Voltage I

OUT

80 µA, 0.5 VCC−0.12 0.5 VCC+0.12 V

REF

VCC=5V

Reference Supply Current, I

OUT

= 0A, (No Load) 120 µA

VCC= 5V (Note 15)

Note 15: Reference supply IDDis supplied for information purposes only, it is not tested.

Comparator DC/AC Characteristics:

4.5V ≤ VCC≤ 5.5V, −55˚C ≤ TA≤ +125˚C

Parameter Conditions Min Typ Max Units

Input Offset Voltage 0.4V

VCC−1.5V

25 mV

Input Common Mode Voltage Range 0.4 V

−1.5 V Voltage Gain 300k V/V Outputs Sink/Source See I/O-Port DC Specifications DC Supply Current (when enabled) V

= 6.0V 250 µA

Response Time TBD mV Step, TBD mV Overdrive, 1 µs

100 pF Load

CAN Comparator DC and AC Characteristics:

4.8V ≤ VCC≤ 5.2V, −40˚C ≤ TA≤ +125˚C

Parameters Conditions Min Typ Max Units

Differential Input Voltage

25 mV

Input Offset Voltage 1.5V

VCC− 1.5V

10 mV

Input Common Mode Voltage Range 1.5 V

− 1.5 V

Input Hysteresis 8mV

DS012067-3

FIGURE 3. MICROWIRE/PLUS Timing Diagram

DS012067-4

FIGURE 4. PWM/CAPTURE Timer

Input/Output Timing Diagram

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Typical Performance Characteristics −55˚C ≤ T

≤ +125˚C

Port D Source Current

DS012067-39

Port D Sink Current

DS012067-40

Ports G/L Source Current

DS012067-41

Port G/L Sink Current

DS012067-42

Ports G/L Weak Pull-Up Source Current

DS012067-43

Dynamic IDDvs V

DS012067-44

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Typical Performance Characteristics −55˚C ≤ T

≤ +125˚C (Continued)

Pin Descriptions

VCCand GND are the power supply pins. CKI is the clock input. The clock can come from a crystal os-

cillator (in conjunction with CKO). See Oscillator Description section.

RESET is the master reset input. See Reset Description section.

The device contains one bidirectional 8-bit I/O port (G), and one 7-bit bidirectional I/O port (L) where each individual bit may be independently configured as an input (Schmitt trigger inputs on ports G and L), 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 DATA register. 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 5

shows the I/O port configurations for the device. 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

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 Lis a 7-bit I/O port. All L-pins have Schmitt triggers on the inputs.

Port L supports Multi-Input Wake Up (MIWU) on all seven pins.

Port L has the following alternate features: L6 MIWU or CMP2OUT or PWM0 or CAPTIN L5 MIWU or CMP2IN− or PWM1 L4 MIWU or CMP2IN+ L3 MIWU or CMP2IN− L2 MIWU or CMP1OUT L1 MIWU or CMP1IN− L0 MIWU or CMP1IN+ Port G is an 8-bit port with 5 I/O pins (G0–G5), an input pin

(G6), and one dedicated output pin (G7). Pins G0–G6 all have Schmitt Triggers on their inputs. G7 serves as the dedicated output pin for the CKO clock output. There are two reg-

Idle I

vs V

DS012067-45

Halt Supply Current

DS012067-46

CAN Tx0 Sink Current

DS012067-47

CAN Tx1 Source Current

DS012067-48

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Pin Descriptions (Continued)

isters associated with the G Port, a data register and a configuration register. Therefore, each of the 6 I/O bits (G0–G5) can be individually configured under software control.

Since G6 is an input only pin and G7 is the dedicated CKO clock output pin the associated bits in the data and configuration registers for G6 and G7 are used for special purpose functions as outlined below. Reading the G6 and G7 data bits will return zeroes.

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.

Config. Register Data Register

G7 HALT G6 Alternate SK IDLE

CAN pins: For the on-chip CAN interface this device has five dedicated pins with the following features:

REF

On-chip reference voltage with the value of VCC/2 Rx0 CAN receive data input pin. Rx1 CAN receive data input pin. Tx0 CAN transmit data output pin. This pin may be put in

the TRI-STATE mode with the TXEN0 bit in the CAN

Bus control register. Tx1 CAN transmit data output pin. This pin may be put in

the TRI-STATE mode with the TXEN1 bit in the CAN

Bus control register. 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 function: G7 CKO Oscillator dedicated output Port D is a 4-bit output port that is preset high when RESET

goes low. The user can tie two or more D port outputs (except D2) together in order to get a higher drive.

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

to prevent the chip from entering special modes. Also

keep the external loading on D2 to less than 1000 pF.

Functional Description

The architecture of the device utilizes a 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 or shift operation in one instruction (t

) cycle time. There are five 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 02F with reset.

All the CPU registers are memory mapped with the exception of the Accumulator (A) and the Program Counter (PC).

PROGRAM MEMORY

Program memory for the device consists of 2048 bytes of ROM. These bytes may hold program instructions or constant data (data tables tor 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 device vector to program memory location 0FF Hex.

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 and SP pointers.

DS012067-5

FIGURE 5. I/O Port Configurations

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Functional Description (Continued)

The device has 64 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, and B are memory mapped into this space at address locations 0FC to 0FE Hex respectively, with the other registers (other than reserved register 0FF) 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.

RESET

The RESET input when pulled low initializes the microcontroller. lnitialization will occur whenever the RESET input is pulled low. Upon initialization, the data and configuration registers for Ports L and G, are cleared, resulting in these Ports being initialized to the TRI-STATE mode. Port D is initialized high with RESET. The PC, PSW, CNTRL, and ICNTRL control registers are cleared. The Multi-Input Wake Up registers WKEN, WKEDG, and WKPND are cleared. The Stack Pointer, SP, is initialized to 02F Hex.

The following initializations occur with RESET:

Port L: TRI-STATE Port G: TRI-STATE Port D: HIGH PC: CLEARED PSW, CNTRL and ICNTRL registers: CLEARED

Accumulator and Timer 1:

RANDOM after RESET with power already applied

RANDOM after RESET at power-on SP (Stack Pointer): Loaded with 2F Hex CMPSL (Comparator control register): CLEARED PWMCON (PWM control register): CLEARED B and X Pointers:

UNAFFECTED after RESET with power already applied

RANDOM after RESET at power-up RAM:

UNAFFECTED after RESET with power already applied

RANDOM after RESET at power-up CAN:

The CAN Interface comes out of external reset in the

“error-active” state and waits until the user’s software

sets either one or both of the TXEN0, TXEN1 bits to “1”.

After that, the device will not start transmission or recep-

tion of a frame until eleven consecutive “recessive” (un-

driven) bits have been received. This is done to ensure

that the output drivers are not enabled during an active

message on the bus.

CSCAL, CTlM, TCNTL, TEC, REC: CLEARED

RTSTAT: CLEARED with the exception of the TBE bit

which is set to 1

RID, RIDL, TID, TDLC: RANDOM

ON-CHIP POWER-ON RESET

The device is designed with an on-chip power-on reset circuit which will trigger a 256 t

delay as VCCrises above the

minimum RAM retention voltage (V

). This delay allows the oscillator to stabilize before the device exits the reset state. The contents of data registers and RAM are unknown following an on-chip power-on reset. The external reset takes priority over the on-chip reset and will deactivate the 256 t

de-

lay if in progress. When using external reset, the external RC network shown

Figure 6

should be used to ensure that the RESET pin is

held low until the power supply to the chip stabilizes. Under no circumstances should the RESET pin be allowed

to float. If the on-chip power-on reset feature is being used, RESET should be connected directly to V

. Be aware of the Power Supply Rise Time requirements specified in the DC Specifications Table. These requirements must be met for the on-chip power-on reset to function properly.

The on-chip power-on reset circuit may reset the device if the operating voltage (V

) goes below Vr.

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. The CKI input frequency is divided by 10 to produce the instruction cycle clock (1/t

Figure 7

shows the Crystal diagram.

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.

DS012067-6

RC>5 x Power Supply Rise Time

FIGURE 6. Recommended Reset Circuit

DS012067-7

FIGURE 7. Crystal Oscillator Diagram

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Oscillator Circuits (Continued)

TABLE 1. Crystal Oscillator Configuration, T

= 25˚C

R1 R2 C1 C2 CKI Freq.

Conditions

(kΩ)(MΩ) (pF) (pF) (MHz)

0 1 30 30–36 10 V

=5V

0 1 30 30–36 4 V

=5V

0 1 200 100–150 0.455 V

=5V

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 be 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

Timers

The device contains a very versatile set of timers (T0, T1, and an 8-bit PWM timer). All timers and associated autoreload/capture registers power up containing random data.

Figure 8

shows a block diagram for timers T1 and T0 on the

device.

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

. The user cannot read or

write to the IDLE Timer T0, which is a count down timer. The Timer T0 supports the following functions:

Exit out of the Idle Mode (See Idle Mode description) Start up delay out of the HALT mode

The IDLE Timer T0 can generate an interrupt when the thirteenth bit toggles. This toggle is latched into the T0PND pending flag, and will occur every 4.096 ms at the maximum clock frequency (t

= 1 µs). A control flag T0EN allows the interrupt from the thirteenth bit of Timer T0 to be enabled or disabled. Setting T0EN will enable the interrupt, while resetting it will disable the interrupt.

TIMER T1

The device has a powerful timer/counter block, T1. The timer block consists of a 16-bit timer, T1, and two sup-

porting 16-bit autoreload/capture registers, R1A and R1B. The timer block has two pins associated with it, T1A and T1B. The pin T1A supports I/O required by the timer block, while the pin T1B is an input to the timer block. The powerful and flexible timer block allows the device to easily perform all timer functions with minimal software overhead. The timer

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FIGURE 8. Timers T1 and T0

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Timers (Continued)

block has three operating modes: Processor Independent PWM mode, External Event Counter mode, and Input Capture mode.

The control bits T1C3, T1C2, andT1C1 allow selection of the different modes of operation.

Mode 1. Processor Independent PWM Mode

As the name suggests, this mode allows the device to generate a PWM signal with very minimal user intervention.

The user only has to define the parameters of the PWM signal (ON time and OFF time). Once begun, the timer block will continuously generate the PWM signal completely independent of the microcontroller. The user software services the timer block only when the PWM parameters require updating.

In this mode the timer T1 counts down at a fixed rate of t

. Upon every underflow the timer is alternately reloaded with the contents of supporting registers, R1A and R1B. The very first underflow of the timer causes the timer to reload from the register R1A. Subsequent underflows cause the timer to be reloaded from the registers alternately beginning with the register R1B.

The T1 Timer control bits, T1C3, T1C2 and T1C1 set up the timer for PWM mode operation.

Figure 9

shows a block diagram of the timer in PWM mode. The underflows can be programmed to toggle the T1A output pin. The underflows can also be programmed to generate interrupts.

Underflows from the timer are alternately latched into two pending flags, T1PNDA and T1PNDB. The user must reset these pending flags under software control. Two control enable flags, T1ENA and T1ENB, allow the interrupts from the timer underflow to be enabled or disabled. Setting the timer enable flag T1ENA will cause an interrupt when a timer underflow causes the R1A register to be reloaded into the timer. Setting the timer enable flag T1ENB will cause an interrupt when a timer underflow causes the R1B register to be reloaded into the timer. Resetting the timer enable flags will disable the associated interrupts.

Either or both of the timer underflow interrupts may be enabled. This gives the user the flexibility of interrupting once per PWM period on either the rising or falling edge of the PWM output. Alternatively, the user may choose to interrupt on both edges of the PWM output.

Mode 2. External Event Counter Mode

This mode is quite similar to the processor independent PWM mode described above. The main difference is that the timer,T1, is clocked by the input signal from the T1A pin. The T1 timer control bits, T1C3, T1C2 and T1C1 allow the timer to be clocked either on a positive or negative edge from the T1A pin. Underflows from the timer are latched into the T1PNDA pending flag. Setting the T1ENA control flag will cause an interrupt when the timer underflows.

In this mode the input pin T1B can be used as an independent positive edge sensitive interrupt input if the T1ENB control flag is set. The occurrence of a positive edge on the T1B input pin is latched into the T1PNDB flag.

Figure 10

shows a block diagram of the timer in External

Event Counter mode.

Note: The PWM output is not available in this mode since the T1A pin is be-

ing used as the counter input clock.

Mode 3. Input Capture Mode

The device can precisely measure external frequencies or time external events by placing the timer block, T1, in the input capture mode.

In this mode, the timer T1 is constantly running at the fixed t

rate. The two registers, R1A and R1B, act as capture registers. Each register acts in conjunction with a pin. The register R1A acts in conjunction with the T1A pin and the register R1B acts in conjunction with the T1B pin.

The timer value gets copied over into the register when a trigger event occurs on its corresponding pin. Control bits, T1C3, T1C2 and T1C1, allow the trigger events to be specified either as a positive or a negative edge. The trigger condition for each input pin can be specified independently.

The trigger conditions can also be programmed to generate interrupts. The occurrence of the specified trigger condition on the T1A and T1B pins will be respectively latched into the pending flags, T1PNDA and T1PNDB. The control flag T1ENA allows the interrupt on T1A to be either enabled or disabled. Setting the T1ENA flag enables interrupts to be generated when the selected trigger condition occurs on the T1A pin. Similarly, the flag T1ENB controls the interrupts from the T1B pin.

Underflows from the timer can also be programmed to generate interrupts. Underflows are latched into the timer T1C0 pending flag (the T1C0 control bit serves as the timer underflow interrupt pending flag in the Input Capture mode). Consequently, the T1C0 control bit should be reset when entering the Input Capture mode. The timer underflow interrupt is enabled with the T1ENA control flag. When a T1A interrupt occurs in the Input Capture mode, the user must check both the T1PNDA and T1C0 pending flags in order to determine whether a T1A input capture or a timer underflow (or both) caused the interrupt.

Figure 11

shows a block diagram of the timer in Input Cap-

ture mode.

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FIGURE 9. Timer 1 in PWM MODE

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Timers (Continued)

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FIGURE 10. Timer 1 in External Event Counter Mode

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FIGURE 11. Timer 1 in Input Capture Mode

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Timers (Continued)

TIMER CONTROL FLAGS

The control bits and their functions are summarized below.

T1C3 Timer mode control T1C2 Timer mode control T1C1 Timer mode control T1C0 Timer Start/Stop control in Modes 1 and 2 (Pro-

cessor Independent PWM and External Event Counter), where 1 = Start, 0 = Stop Timer Underflow Interrupt Pending Flag in Mode 3 (Input Capture)

T1PNDA Timer Interrupt Pending Flag T1ENA Timer Interrupt Enable Flag

1 = Timer Interrupt Enabled

0 = Timer Interrupt Disabled T1PNDB Timer Interrupt Pending Flag T1ENB Timer Interrupt Enable Flag

1 = Timer Interrupt Enabled

0 = Timer Interrupt Disabled

The timer mode control bits (T1C3, T1C2 and T1C1) are detailed below:

Mode T1C3 T1C2 T1C1 Description

Interrupt A

Source

Interrupt B

Source

Timer

Counts On

1 0 1 PWM: T1A Toggle Autoreload RA Autoreload RB t

1 0 0 PWM: No T1A

Toggle

Autoreload RA Autoreload RB

0 0 0 External Event

Counter

Timer Underflow

Pos. T1B Edge Pos. T1A

Edge

0 0 1 External Event

Counter

Timer Underflow

Pos. T1B Edge Pos. T1A

Edge

0 1 0 Captures: Pos. T1A Edge Pos. T1B Edge t

T1A Pos. Edge or Timer T1B Pos. Edge Underflow

1 1 0 Captures: Pos. T1A Neg. T1B t

T1A Pos. Edge Edge or Timer Edge T1B Neg. Edge Underflow

0 1 1 Captures: Neg. T1A Neg. T1B t

T1A Neg. Edge Edge or Timer Edge T1B Neg. Edge Underflow

1 1 1 Captures: Neg. T1A Neg. T1B t

T1A Neg. Edge Edge or Timer Edge T1B Neg. Edge Underflow

HIGH SPEED, CONSTANT RESOLUTION PWM TIMER

The device has one processor independent PWM timer.The PWM timer operates in two modes: PWM mode and capture mode. In PWM mode the timer outputs can be programmed to two pins PWM0 and PWM1. In capture mode, pin PWM0 functions as the capture input.

Figure 12

shows a block dia-

gram for this timer in capture mode and

Figure 13

shows a

block diagram for the timer in PWM mode.

PWM Timer Registers

The PWM Timer has three registers: PWMCON, the PWM control register, RLON, the PWM on-time register and PSCAL, the prescaler register.

PWM Prescaler Register (PSCAL) (Address X’00A0)

The prescaler is the clock source for the counter in both PWM mode and in frequency monitor mode.

PSCAL is a read/write register that can be used to program the prescaler.The clock source to the timer in both PWM and capture modes can be programmed to CKI/N where N =

PSCAL + 1, so the maximum PWM clock frequency = CKI and the minimum PWM clock frequency = CKI/256. The processor is able to modify the PSCAL register regardless of whether the counter is running or not and the change in frequency occurs with the next underflow of the prescaler (CKPWM).

PWM On-time Register (RLON) (Address X’00A1)

RLON is a read/write register. In PWM mode the timer output will be a “1” for RLON counts out of a total cycle of 255 PWM clocks. In capture mode it is used to program the threshold frequency.

The PWM timer is specially designed to have a resolution of 255 PWM clocks. This allows the duty cycle of the PWM output to be selected between 1/255 and 254/255. A value of 0 in the RLON register will result in the PWM output being continuously low and a value of 255 will result in the PWM output being continuously high.

Note: The effect of changing the RLON register during active PWM mode op-

eration is delayed until the boundary of a PWM cycle. In capture mode the effect takes place immediately.

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Timers (Continued)

PWM Control Register (PWMCON) (Address X’00A2)

Reserved ESEL PWPND PWIE PWMD PWON PWEN1 PWEN0 Bit 7 Bit 0

The PWMCON Register Bits are: Reserved This bit is reserved and must be zero. ESEL Edge select bit, “1” for falling edge, “0” for rising

edge. PWPND PWM interrupt pending bit. PWIE PWM interrupt enable bit. PWMD PWM Mode bit, “1” for PWM mode, “0” for fre-

quency monitor mode. PWON PWM start Bit, “1” to start timer, “0” to stop timer.

PWEN1 Enable PWM1 output function on I/O port.

Note: The associated bits in the configuration and data register of the I/O-

port have to be setup as outputs and/or inputs in addition to setting the PWEN bits.

PWEN0 Enable PWM0 output/input function on I/O port.

PWM Mode

The PWM timer can generate PWM signals at frequencies up to 39 kHz (

tc= 1 µs) with a resolution of 255 parts. Lower PWM frequencies can be programmed via the prescaler.

If the PWM mode bit (PWMD) in the PWM configuration register (PWMCON) is set to “1” the timer operates in PWM mode. In this mode, the timer generates a PWM signal with

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FIGURE 12. PWM Timer Capture Mode Block Diagram

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FIGURE 13. PWM Timer PWM Mode Block Diagram

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Timers (Continued)

a fixed, non-programmable repetition rate of 255 PWM clock cycles. The timer is clocked by the output of an 8-bit, programmable prescaler, which is clocked with the chip’s CKI frequency. Thus the PWM signal frequency can be calculated with the formula:

Selecting the PWM mode by setting PWMD to “1”, but not yet starting the timer (PWON is “0”), will set the timer output to “1”.

The contents of an 8-bit register, RLON, multiplied by the clock cycle of the prescaler output defines the time between overflow (or starting) and the falling edge of the PWM output.

Once the timer is started, the timer output goes low after RLON cycles and high after a total of 255 cycles. The procedure is continually repeated. In PWM mode the timer is available at pins PWM0 and/or PWM1, provided the port configuration bits for those pins are defined as outputs and the PWEN0 and/or PWEN1 bits in the PWMCON register are set.

The PWM timer is started by the software setting the PWON bit to “1”. Starting the timer initializes the timer register. From this point, the timer will continually generate the PWM signal, independent of any processor activity, until the timer is stopped by software setting the PWON bit to “0”. The processor is able to modify the RLON register regardless of whether the timer is running. If RLON is changed while the timer is running, the previous value of RLON is used for comparison until the next overflow occurs, when the new value of RLON is latched into the comparator inputs.

When the timer overflows, the PWM pending flag (PWPND) is set to “1”. If the PWM interrupt enable bit (PWIE) is also set to “1”, timer overflow will generate an interrupt. The PWPND bit remains set until the user’s software writes a “0” to it. If the software writes a “1” to the PWPND bit, this has no effect. If the software writes a “0” to the PWPND bit at the same time as the hardware writes to the bit, the hardware has precedence.

Note: The software controlling the duty cycle is ableto change the PWM duty

cycle without having to wait for the timer overflow.

Figure 14

shows how the PWM output is implemented. The PWM Timer output is set to “1” on an overflow of the timer and set to “0” when the timer is greater than RLON. The output can be multiplexed to two pins.

Capture Mode

If the PWM mode bit (PWMD) is set to “0” the PWM Timer operates in capture mode. Capture mode allows the programmer to test whether the frequency of an external source exceeds a certain threshold.

If PWMD is “0” and PWON is “0”, the timer output is set to “0”. In capture mode the timer output is available at pin PWM1, provided the port configuration register bit for that pin is set up as an output and the PWEN1 bit in the PWMCON register is set. Setting PWON to “1” will initialize the timer register and start the counter.A rising edge, or if selected, a falling edge, on the FMONIN input pin will initialize the timer register and clear the timer output. The counter continues to count up after being initialized. The ESEL bit determines whether the active edge is a rising or a falling edge.

If, in capture mode PWM0 is configured incorrectly as an output and is enabled via the PWEN0 bit, the timer output will feedback into the PWM block as the timer input.

The contents of the counter are continually compared with the RLON register. If the frequency of the input edges is sufficiently high, the contents of the counter will always be less

than the value in RLON. However, if the frequency of the input edges is too low, the free-running counter value will count up beyond the value in RLON.

When the counter is greater than RLON, the PWM timer output is set to “1”. It is set to “0” by a detected edge on the timer input or when the counter overflows. When the counter be-

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FIGURE 14. PWM Mode Operation

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