
1996 Microchip Technology Inc.
DS30412C-page 115
PIC17C4X
BSF
Bit Set f
Syntax:
[
label ] BSF
f,b
Operands:
0
≤ f ≤ 255
0
≤ b ≤ 7
Operation:
1
→ (f<b>)
Status Affected:
None
Encoding:
1000
0bbb
ffff
Description:
Bit 'b' in register 'f' is set.
Words:
1
Cycles:
1
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register 'f'
Execute
Write
register 'f'
Example:
BSF
FLAG_REG, 7
Before Instruction
FLAG_REG= 0x0A
After Instruction
FLAG_REG= 0x8A
BTFSC
Bit Test, skip if Clear
Syntax:
[
label ] BTFSC f,b
Operands:
0
≤ f ≤ 255
0
≤ b ≤ 7
Operation:
skip if (f<b>) = 0
Status Affected:
None
Encoding:
1001
1bbb
ffff
Description:
If bit 'b' in register ’f' is 0 then the next
instruction is skipped.
If bit 'b' is 0 then the next instruction
fetched during the current instruction exe-
cution is discarded, and a NOP is exe-
cuted instead, making this a two-cycle
instruction.
Words:
1
Cycles:
1(2)
Q Cycle Activity:
Q1
Q2
Q3
Q4
Decode
Read
register 'f'
Execute
NOP
If skip:
Q1
Q2
Q3
Q4
Forced NOP
NOP
Execute
NOP
Example:
HERE
FALSE
TRUE
BTFSC
:
FLAG,1
Before Instruction
PC
=
address (HERE)
After Instruction
If FLAG<1>
=
0;
PC
=
address (TRUE)
If FLAG<1>
=
1;
PC
=
address (FALSE)