background image

CO

P

8

2

0

C

 J/

C

O

P8

22

C

 J/

C

O

P8

23

C

 J

M o d u la to r /T im e r

The Modulator/Timer contains an 8-bit counter and an 8-bit 
autoreload register (MODRL address OCF Hex). The Modu­
lator/Timer  has  two  modes  of  operation,  selected  by  the 
control  bit  MC3.  The  Modulator/Timer  Control  bits  MC1, 
MC2 and  MC3  reside in CNTRL2  Register.

MODE 1: MODULATOR

The Modulator is used to generate high frequency pulses on 
the modulator output pin  (L7). The  L7 pin  should be config­
ured  as  an  output.  The  number of  pulses  is  determined  by 
the 8-bit down counter. Under software control the modula­
tor input clock can  be either CKI  or tC. The tC clock  is de­

rived by dividing down the oscillator clock by a factor of 10. 

Three  control  bits  (MC1,  MC2,  and  MC3)  are  used  for the 

Modulator/Timer output control. When  MC2  =   1  and  MC3 

=   1,  CKI  is used  as the  modulator input clock. When  MC2 
=  0, and MC3  =   1, tC is used as the modulator input clock. 

The  user  loads  the  counter  with  the  desired  number  of 
counts  (256  max)  and  sets  MC1  to  start the  counter.  The 

modulator  autoreload  register  is  loaded  with  n-1  to  get  n 
pulses. CKI  or tc pulses are routed to the modulator output 
(L7)  until  the  counter  underflows 

(Figure  13).

  Upon  under­

flow the  hardware  resets  MC1  and  stops the  counter.  The 

L7 pin goes low and stays low until the counter is restarted 

by the user program. The user program has the responsibili­
ty to timeout the  low time.  Unless the  number of counts  is 
changed, the user program does not have to load the coun­
ter each time the counter is started. The counter can simply 
be  started by setting the  MC1  bit.  Setting  MC1  by software 
will  load the  counter with the value of the autoreload  regis­
ter. The software can reset MC1  to stop the counter.

MODE 2: PWM TIMER

The  counter  can  also  be  used  as  a  PWM  Timer.  In  this 
mode,  an  8-bit  register  is  used  to  serve  as  an  autoreload 
register (MODRL).

a. 50% Duty Cycle:

When MC1  is 1  and MC2,  MC3 are 0, a 50% duty cycle free 
running signal is generated on the L7 output pin 

(Figure  14).

 

The  L7  pin  must  be  configured  as  an  output  pin.  In  this 

mode  the  8-bit  counter  is  clocked  by  tC.  Setting  the  MC1

control  bit  by  software  loads the  counter with  the  value  of 
the autoreload  register and  starts the  counter. The counter 
underflow toggles the  (L7)  output pin.  The  50%  duty cycle 
signal  will  be  continuously generated  until  MC1  is  reset  by 
the user program.

b. Variable Duty Cycle:

When  MC3  =   0  and  MC2  =   j , a variable duty cycle  PWM 
signal  is  generated  on  the  L7  output  pin.  The  counter  is 
clocked  by tC.  In  this  mode  the  16-bit  timer T1  along  with 
the 8-bit down counter are used to generate a variable duty 
cycle  PWM signal. The timer T1  underflow sets MC1  which 

starts the down counter and it also sets L7  high  (L7 should 
be  configured  as  an  output).When  the  counter  underflows 

the  MC1  control  bit  is  reset  and  the  L7  output  will  go  low 

until the next timer T1  underflow. Therefore, the width of the 

output pulse is controlled by the 8-bit counter and the pulse 
duration is controlled by the 16-bit timer T1 

(Figure  15).

 Tim­

er T1  must be configured in “ PWM  Mode/Toggle TIO Out” 
(CNTRL1  Bits 7,6,5  =  101).

Table VII shows the different operation modes for the Mod­
ulator/Timer.

TABLE VII. Modulator/Timer Modes

Control Bits in

 

CNTRL2(00CC)

Operation Mode

 

L7 Function

MC3

MC2

MC1

0

0

0

Normal I/O

0

0

1

50%  Duty Cycle Mode (Clocked 
by tc)

0

1

X

Variable Duty Cycle Mode 

(Clocked by tc) Using Timer 1 
Underflow

1

0

X

Modulator Mode (Clocked by tc)

1

1

X

Modulator Mode (Clocked by 
CKI)

Note: 

M C 1 ,  M C 2   a n d   M C 3   c o n tro l  b its   a re   c le a re d   u p o n   re se t.

Internal Data Bus

256  PULSES  (MAX.)

juin_n

CKI  OR  ^

(50%   DUTY  CYCLE)

_n_n_.._n_

t

TRIGGERED  BY 

SOFTWARE

TRIGGERED  BY 
SOFTWARE

FIGURE 13. Mode 1: Modulator Block Diagram/Output Waveform

TL/DD/11208-16

1-64

Summary of Contents for COP820CJ

Page 1: ...perating at a 1 jus per in struction rate Features Low cost 8 bit Microcontroller n Fully static CMOS n 1 jus instruction time Low current drain Low current static HALT mode Single supply operation 2 5V to 6 0V 1024 x 8 on chip ROM 64 bytes on chip RAM WATCHDOG Timer Comparator Modulator Timer High speed PWM Timer for IR Transmission Multi Input Wakeup on the 8 bit Port L Brown Out Protection 4 hi...

Page 2: ...5 mA CKI 4 MHz Vcc 4 0V tc 2 5 fis 2 0 mA CKI 1 MHz Vcc 4 0V tc 10 jxs 1 5 mA HALT Current with Brown Out Disbled Note 3 VCc 6V CKI 0 MHz 1 10 p A HALT Current with Brown Out Enabled VCc 6V CKI 0 MHz 50 110 juA BrownOut Trip Level 1 8 3 1 4 2 Brown Out Enabled INPUT LEVELS V H V l Reset CKI Logic High 0 8 VCC V Logic Low All Other Inputs 0 2 VCC V Logic High 0 7 VCC V Logic Low 0 2 VCC V Hi Z Inpu...

Page 3: ...low Vcc The effective resistance to Vcc is 750ft typical These two pins will not latch up The voltage at the pins must be limited to less than 14V AC Electrical Characteristics 40 C Ta 85 C unless otherwise specified Parameter Conditions Min Typ Max Units Instruction Cycle Time tc Crystal Resonator 4 5V Vcc 6 0V 1 DC JUS 2 5V VCc 4 5V 2 5 DC JUS R C Oscillator 4 5V VCc 6 0V 3 DC JUS 2 5V VCc 4 5V ...

Page 4: ...5 S K 2 27 G2 G 6 S I 3 26 G1 G 7 C K 0 4 25 G 0 IN T C K I 5 24 RESET w c r snrv CC wnw I0 7 22 D3 1 1 8 21 02 I 2 9 20 01 I 3 10 19 D O L0 C M P 0U T 11 18 L7 M0D0UT L1 CMPIN 12 17 L6 L2 CMPIN 13 16 L5 L3 14 15 L4 T L D D 11208 3 Top View Order Number COPCJ820 XXX N or COPCJ820 XXX WM G4 S0 1 20 G3 TI0 G 5 S K 2 19 G2 G6 SI 3 18 G1 07 C K0 4 17 C O IM T CKI 5 16 RESET vc c 6 15 GND L0 CMP0UT 7 1...

Page 5: ...COP820CJ COP822CJ COP823CJ 1 54 ...

Page 6: ... MIWU high sink current capability L6 MIWU high sink current capability L7 MIWU or MODOUT high sink current capability The selection of alternate Port L functions is done through registers WKEN 00C9 to enable MIWU and CNTRL2 OOCC to enable comparator and modulator All eight L pins have Schmitt Triggers on their inputs PORT G is an 8 bit port with 6 I O pins G0 G5 and 2 input pins G6 G7 All eight G...

Page 7: ...emory is addressed directly by the in struction or indirectly through B X and SP registers The device has 64 bytes of RAM Sixteen bytes of RAM are mapped as registers these can be loaded immediately decremented and tested Three specific registers X B and SP are mapped into this space the other registers are avail able for general usage Any bit of data memory can be directly set reset or tested All...

Page 8: ...a 256tc delay This delay allows the oscillator to stabilize before the device ex its the reset state The delay is not used if the clock option is either R C or external clock The contents of data registers and RAM are unknown following a Brown Out reset The external reset takes priority over Brown Out Reset and will deactivate the 256 tc cycles delay if in progress The Brown Out reset takes priori...

Page 9: ...ke a R C oscillator CKO is available as a general purpose input and or HALT control Table II shows variation in the oscilla tor frequencies as functions of the component R and C values Functional Description Continued TABLE I Crystal Oscillator Configuration R1 R2 C1 C2 CKI Freq Conditions kn Mft PF PF MHz 0 1 30 30 36 10 Vcc 5V 0 1 30 30 36 4 VCC 5V 5 6 1 100 100 156 0 455 in II o o TABLE II RC O...

Page 10: ... and freuqency stability The WATCHDOG timer consisting of an 8 bit prescaler followed by an 8 bit counter is used to gen erate a fixed delay of 256tc to ensure that the oscillator has indeed stabilized before allowing instruction execution In this case upon detecting a valid WAKEUP signal only the oscillator circuitry is enabled The WATCHDOG Counter and Prescaler are each loaded with a value of FF...

Page 11: ...here tc is the instruction cycle time MICROWIRE PLUS OPERATION Setting the BUSY bit in the PSW register causes the MI CROWIRE PLUS arrangement to start shifting the data It gets reset when eight data bits have been shifted The user may reset the BUSY bit by software to allow less than 8 bits to shift The device may enter the MICROWIRE PLUS mode either as a Master or as a Slave Figure 7 shows how t...

Page 12: ...tive edge Upon underflow the contents of the register R1 are automatically copied into the counter The underflow can also be programmed to generate an interrupt Figure 9 T im er C o u n ter The device has a powerful 16 bit timer with an associated 16 bit register enabling it to perform extensive timer func tions The timer T1 and its register R1 are each organized as two 8 bit read write registers ...

Page 13: ...ms The WATCHDOG can be en abled or disabled only once after the device is reset as a result of brown out reset or external reset On power up the WATCHDOG is disabled The WATCHDOG is enabled by writing a 1 to WDREN bit resides in WDREG register Once enabled the user program should write periodically into the 8 bit counter before the counter underflows The 8 bit counter WDCNT is memory mapped at add...

Page 14: ...he HALT mode It is a read only bit WDREN bit resides in a separate register bit 0 of WDREG This bit enables the WATCHDOG timer to generate a reset The bit is cleared upon Brown Out reset or external reset The bit under software control can be written to only once once written to the hardware does not allow the bit to be changed during program execution WDREN 1 WATCHDOG reset is enabled WDREN 0 WAT...

Page 15: ... Timer In this mode an 8 bit register is used to serve as an autoreload register MODRL a 50 Duty Cycle When MC1 is 1 and MC2 MC3 are 0 a 50 duty cycle free running signal is generated on the L7 output pin Figure 14 The L7 pin must be configured as an output pin In this mode the 8 bit counter is clocked by tC Setting the MC1 control bit by software loads the counter with the value of the autoreload...

Page 16: ... REGISTER r 4 INTERNAL DATA BUS k i k 7 6 5 f 0 AUTO RELOAD MC3 MC2 MC1 8 BIT 0 1 R Q S I ILK 8 BIT START STOP 1 IIDERTLCV CNTRL2 REGISTER TIMER Tt UNDERFLOW L7 PIN T L D D 11208 19 UNDERFLOW I I UNDERFLOW u 256 MAX CONTROLLED BY T1 FIGURE 15 Mode 2b Variable Duty Cycle Output T L D D 11208 20 1 65 COP820CJ COP822CJ COP823CJ ...

Page 17: ...rify this procedure Suppose we wish to change the edge select from positive low going high to negative high going low for L port bit 5 where bit 5 has previously been enabled for an input The program would be as follows RBIT 5 WKEN SBIT 5 WKEDG RBIT 5 WKPND SBIT 5 WKEN If the L port bits have been used as outputs and then changed to inputs with Multi Input Wakeup a safety proce dure should also be...

Page 18: ... onto the stack and the stack pointer SP is decremented twice The Global Interrupt Enable GIE bit is reset to disable further interrupts The microcontroller then vectors to the address 00FFH and resumes execution from that address This process takes 7 cycles to complete At the end of the interrupt subroutine any of the following three instructions return the processor back to the main pro gram RET...

Page 19: ...Y ENI GIE The Half Carry bit is also effected by all the instructions that effect the Carry flag The flag values depend upon the in struction For example after executing the ADC instruction the values of the Carry and the Half Carry flag depend upon the operands involved However instructions like SET C and RESET C will set and clear both the carry flags Table XIII lists the instructions that effec...

Page 20: ...the B or X pointer This is a register indirect mode that automati cally post increments or post decrements the B or X pointer after executing the instruction DIRECT The instruction contains an 8 bit address field that directly points to the data memory for the operand IMMEDIATE The instruction contains an 8 bit immediate field as the op erand SHORT IMMEDIATE This addressing mode issued with the LD...

Page 21: ...Set bit 1 to bit Mem bit 0 to 7 immediate RBIT Reset bit 0 to bit Mem IFBIT If bit If bit Mem is true do next instr X Exchange A with memory A Mem LD A Load A with memory A 4 Meml LD mem Load Direct memory Immed Mem 4 Imm LDReg Load Register memory Immed Reg Imm X Exchange A with memory B A B B B 1 X Exchange A with memory X A X X X 1 LD A Load A with memory B A B B B 1 LD A Load A with memory X A...

Page 22: ...1 71 COP820CJ COP822CJ COP823CJ ...

Page 23: ...1 3 4 2 2 OR 1 1 3 4 2 2 XOR 1 1 3 4 2 2 IFEQ 1 1 3 4 2 2 IFGT 1 1 3 4 2 2 IFBNE 1 1 DRSZ 1 3 SBIT 1 1 3 4 RBIT 1 1 3 4 IFBIT 1 1 3 4 Memory Transfer Instructions Bytes Cycles Register Indirect B X Direct Immed Register Indirect Auto Incr Deer B B X X XA 1 1 1 3 2 3 1 2 1 3 LD A 1 1 1 3 2 3 2 2 1 2 1 3 LD B lmm 1 1 LD B lmm 2 3 LD Mem lmm 3 3 2 2 LD Reg lmm 2 3 Memory location addressed by B or X ...

Page 24: ...direct address opcode value opcode class or im mediate operand Complex breakpoints can be ANDed and ORed together Trace information consists of address bus values opcodes and user selectable probe clips status ex ternal event lines The trace buffer can be viewed as raw hex or as disassembled instructions The probe clip bit val ues can be displayed in binary hex or digital waveform for mats During ...

Page 25: ...dering Information Assembler Ordering Information Part Number Package Voltage Range Emulates MH 820CJ20D5PC 20 DIP 4 5V 5 5V COP822CJ MHW 820CJ20DWPC 20 DIP 2 3V 6 0V COP822CJ MHW 820CJ28D5PC 28 DIP 4 5V 5 5V COP820CJ MHW 820CJ28DWPC 28 DIP 2 3V 6 0V COP820CJ Part Number Description Manual COP8 DEV IBMA COP8 Assembler Linker Librarian for IBM PC XT AT or compatible 424410632 001 MACRO CROSS ASSEMB...

Page 26: ... by the Microcontroller Applications Group The Dial A Helper is an Electronic Bul letin Board information system INFORMATION SYSTEM The Dial A Helper system provides access to an automated information storage and retrieval system that may be ac cessed over standard dial up telephone lines 24 hours a day The system capabilities include a MESSAGE SECTION electronic mail for communications to and fro...

Reviews: