PIC16C55X(A)
BCF
Bit Clear f
BTFSC
Bit Test, Skip if Clear
Syntax:
Operands:
[ label ] BCF f,b
Syntax:
[ label ] BTFSC f,b
0 ≤ f ≤ 127
0 ≤ b ≤ 7
Operands:
0 ≤ f ≤ 127
0 ≤ b ≤ 7
Operation:
Status Affected:
Encoding:
Description:
Words:
0 → (f<b>)
Operation:
skip if (f<b>) = 0
None
None
Status Affected:
Encoding:
01
00bb
bfff
ffff
01
10bb
bfff
ffff
If bit 'b' in register 'f' is '0' then the next
instruction is skipped.
Bit 'b' in register 'f' is cleared.
Description:
1
1
If bit 'b' is '0' then the next instruction
fetched during the current instruction
execution is discarded, and a NOP is
executed instead, making this a
two-cycle instruction.
Cycles:
BCF
FLAG_REG, 7
Example
Before Instruction
FLAG_REG = 0xC7
After Instruction
Words:
Cycles:
Example
1
1(2)
FLAG_REG = 0x47
HERE
FALSE
TRUE
BTFSC FLAG,1
GOTO
PROCESS_CODE
•
•
•
Before Instruction
PC
=
address HERE
After Instruction
if FLAG<1> = 0,
PC =
address TRUE
if FLAG<1>=1,
PC =
address FALSE
BSF
Bit Set f
Syntax:
Operands:
[ label ] BSF f,b
0 ≤ f ≤ 127
0 ≤ b ≤ 7
Operation:
Status Affected:
Encoding:
Description:
Words:
1 → (f<b>)
None
01
01bb
bfff
ffff
Bit 'b' in register 'f' is set.
1
1
Cycles:
BSF
FLAG_REG,
7
Example
Before Instruction
FLAG_REG = 0x0A
After Instruction
FLAG_REG = 0x8A
DS40143B-page 54
Preliminary
1997 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
