PIC16F627A Datasheet, PDF (117/168 Pages) Microchip Technology – FLASH-Based 8-Bit CMOS Microcontrollers

PIC16F627A/628A/648A
BTFSS
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example
Bit Test f, Skip if Set
[ label ] BTFSS f,b
0 ≤ f ≤ 127
0≤b<7
skip if (f<b>) = 1
None
01
11bb bfff ffff
If bit 'b' in register 'f' is '1' then the
next instruction is skipped.
If bit 'b' is '1', then the next instruc-
tion fetched during the current
instruction execution, is discarded
and a NOP is executed instead,
making this a two-cycle instruc-
tion.
1
1(2)
HERE
FALSE
TRUE
BTFSS
GOTO
•
•
•
REG1
PROCESS_CODE
Before Instruction
PC = address HERE
After Instruction
if FLAG<1> = 0,
PC = address FALSE
if FLAG<1> = 1,
PC = address TRUE
CALL
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example
Call Subroutine
[ label ] CALL k
0 ≤ k ≤ 2047
(PC)+ 1→ TOS,
k → PC<10:0>,
(PCLATH<4:3>) → PC<12:11>
None
10
0kkk kkkk kkkk
Call Subroutine. First, return
address (PC+1) is pushed onto
the stack. The eleven bit imme-
diate address is loaded into PC
bits <10:0>. The upper bits of
the PC are loaded from
PCLATH. CALL is a two-cycle
instruction.
1
2
HERE CALL THERE
Before Instruction
PC = Address HERE
After Instruction
PC = Address THERE
TOS = Address HERE+1
CLRF
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Example
Clear f
[ label ] CLRF f
0 ≤ f ≤ 127
00h → (f)
1→Z
Z
00
0001 1fff ffff
The contents of register 'f' are
cleared and the Z bit is set.
1
1
CLRF REG1
Before Instruction
REG1 = 0x5A
After Instruction
REG1 = 0x00
Z
=1
 2002 Microchip Technology Inc.
Preliminary
DS40044A-page 115