Specifications of some common
PIC's
| Device | Pins | I/O | ROM | RAM | Max. Freq. | Voltage range | Features |
| P12C508 | 8 | 6 max. | 512 bytes | 25 | 20 | 2.5-6.25 | TMR0,WDT, SLEEP, Code protection, POR, 2 Level Stack, interrupts, internal oscillator. |
| P12C509 | 8 | 6 max. | 512 bytes | 25 | 20 | 2.5-6.25 | As P12C508 |
| P16C54 | 18 | 12 | 512 bytes | 25 | 20 | 2.5-6.25 | TMR0, WDT, SLEEP Code protection, POR,2 Level Stack. |
| P16C55 | 28 | 20 | 512 bytes | 24 | 20 | 2.5-6.25 | As P16C54 |
| P16C56 | 18 | 12 | 1kbyte | 25 | 20 | 2.5-6.25 | As P16C54 |
| P16C57 | 28 | 20 | 2kbytes | 72 | 20 | 2.5-6.25 | As P16C54 |
| P16C71 | 18 | 13 | 1kbyte | 36 | 20 | 3-6 | 4 A/D channels, 8 Level Stack, Interrupts, +those of P16C54. |
| P16C73 | 28 | 22 | 4kbytes | 192 | 20 | 3-6 | 5 A/D channels,TMR1, TMR2, Serial Interface + those of P16C71. |
| P16C84 | 18 | 13 | 1kbyte | 36 | 10 | 2-6 | 1K EEPROM, 8 Level Stack, Interrupts, + those of P16C54. |
Instruction Set for most PIC's
addlw number
- (NOT FOR PIC16C5X
SERIES) - adds a number with the number in the working register.
addwf FileReg, f
- adds the number
in the working register to the number in a file register (FileReg) and
puts the result in the file register.
addwf FileReg, w
- adds the number
in the working register to the number in a file register (FileReg) and
puts the result back into the working register, leaving the file register
unchanged.
andlw number
- ANDs a number with
the number in the working register, leaving the result in the working reg.
andwf FileReg, f
- ANDs the number
in the working register with the number in a file register (FileReg) and
puts the result in the file register
bcf FileReg, bit
- clears a bit in
a file register (FileReg), i.e. makes the bit 0
bsf FileReg, bit
- sets a bit in a
file register (FileReg), i.e. makes the bit 1
btfsc FileReg, bit
- tests a bit in
a file register (FileReg) and skips the next instruction if the result
is clear (i.e. if that bit is 0).
btfss FileReg, bit
- tests a bit in
a file register (FileReg) and skips the next instruction if the result
is set (i.e. if that bit is 1).
call AnySub
- makes the chip
call a subroutine(AnySub), after which it will return to where it left
off.
clrf FileReg
- clears (makes 0)
the number in a file register (FileReg).
clrw
- clears the working
register.
clrwdt
- clears the watchdog
timer.
comf FileReg, f
- complements (inverts
- ones become zeroes, zeroes become ones) the number in a file register
(FileReg), leaving the result in the file register.
decf FileReg, f
- decrements (subtracts
one from) a file register (FileReg) and puts the result in the file register.
decfsz FileReg, f
- decrements a file
register (FileReg) and if the result is zero it skips the next instruction.
The result is put in the file register.
goto Anywhere
- makes the chip
go to somewhere in the program which YOU have labelled 'Anywhere'.
incf FileReg, f
- increments (adds
one to) a file register (FileReg) and puts the result in the file register.
incfsz FileReg, f
- increments a file
register (FileReg) and if the result is zero it skips the next instruction.
The result is put in the file register.
iorlw number
- inclusive ORs a
number with the number in the working register.
iorwf FileReg, f
- inclusive ORs the
number in the working register with the number in a file register (FileReg)
and puts the result in the file register.
movfw FileReg or movf
FileReg, w
- moves (copies)
the number in a file register (FileReg) in the working register
movlw number
- moves (copies)
a number into the working register.
movwf FileReg
- moves (copies)
the number in the working register into a file register (FileReg).
nop
- this stands for
: no operation, in other words - do nothing, (it seems useless, but it's
actually quite useful!)
option
- (NOT TO BE USED
EXCEPT IN PIC16C5X SERIES) - takes the number in the working register and
moves it into the option register.
retfie
- (NOT FOR PIC16C5X
SERIES) - returns from a subroutine and enables the Global Interrupt Enable
bit.
retlw number
- returns from a
subroutine with a particular number (literal) in the working register.
return
- (NOT FOR PIC16C5X
SERIES) - returns from a subroutine.
rlf FileReg, f
- rotates the bits
in a file register (FileReg) to the left, putting the result in the file
register.
rrf FileReg, f
- rotates the bits
in a file register (FileReg) to the right, putting the result in the file
register.
sleep
- sends the PIC to
sleep, a lower power consumption mode.
sublw number
- (NOT FOR PIC16C5X
SERIES) - subtracts the number in the working register from a number.
subwf FileReg, f
- subtracts the number
in the working register from the number in a file register (FileReg) and
puts the result in the file register.
swapf FileReg, f
- swaps the two halves
of the 8 bit binary number in a file register (FileReg), leaving the result
in the file register.
tris PORTX
- (NOT TO BE USED
EXCEPT IN PIC16C5X SERIES) - uses the number in the working register to
specify which bits of a port are inputs (correspond to a binary 1) and
which are outputs (correspond to 0).
xorlw number
- exclusive ORs a
number with the number in the working register.
xorwf FileReg, f
- exclusive ORs the
number in the working register with the number in a file register (FileReg)
and puts the result in the file register.
Assignments of two of the File
Registers (option and status)
| Option register bit assignments | |||||||||
| bit no | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | |
| - | - | RTS | RTE | PSA | PS2 | PS1 | PS0 | prescaler
rates |
|
| 0 | 0 | 0 | 1:2 | ||||||
| 0 | 0 | 1 | 1:4 | ||||||
| 0 | 1 | 0 | 1:8 | ||||||
| 0 | 1 | 1 | 1:16 | ||||||
| 1 | 0 | 0 | 1:32 | ||||||
| 1 | 0 | 1 | 1:64 | ||||||
| 1 | 1 | 0 | 1:128 | ||||||
| 1 | 1 | 1 | 1:256 | ||||||
| (P16C5x) Unassigned
(P16C71) Port B pull-up Enable
(P12C50x) Enable Wake-up on Pin Change
|
(P16C5x) Unassigned
(P16C71) Interrupt Edge Select
(P12C50x) Enable Weak Pull-ups
|
Timer (TMR0) signal source
0 - if you want to count an internal signal 1 - if you want to count an external signal |
Timer (TMR0) increment mode
0 - if you want to count up on a negative going edge 1 - if you want to count up on a positive going edge |
prescaler assignment:
0 - if you want the prescaler to be used by the timer (TMR0) 1 - if you want the prescaler to be used by the watchdog time (WDT) |
| Status register bit assignments | ||||||||
| bit no | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 |
| bit label | PA2 | PA1 | PA0 | TO | PD | Z | DC | C |
| Do not use this bit for anything,
in order to maintain upward compatibility. |
see PA0 (adjacent) | (P16C54 and 55)
Do not use these bits for anything, in order to maintain upward compatibility. (P16C56 and 57)
(P12C7x)
|
Timeout bit.
See table. |
Power down bit. See table. | Zero Flag :
1 : The result was 0 0 : The result wasn't 0 |
Digit Carry/Borrow Flag:
As Carry Flag except concerning the lower nibbles of numbers in question. |
Carry/Borrow Flag:
Reacts to carrying or borrowing with arithmetic operations, and to the rrf and rlf instructions. |
| Timeout and power down registers | |||
| bit no. | 5 | 4 | |
| bit label | TO | PD | Reset caused by... |
| 0 | 0 | WDT wakeup from sleep | |
| 0 | 1 | WDT timeout (not during sleep) | |
| 1 | 0 | MCLR wakeup from sleep | |
| 1 | 1 | Power - up |
©1999
Joseph Birr-Pixton
email:
[email protected]