Datasheet

PIC16C71X
DS30272A-page 72  1997 Microchip Technology Inc.
BCF Bit Clear f
Syntax: [
label ] BCF f,b
Operands: 0 ≤ f ≤ 127
0 ≤ b ≤ 7
Operation: 0 → (f<b>)
Status Affected: None
Encoding:
01 00bb bfff ffff
Description: Bit 'b' in register 'f' is cleared.
Words: 1
Cycles: 1
Q Cycle Activity: Q1 Q2 Q3 Q4
Decode Read
register
'f'
Process
data
Write
register 'f'
Example
BCF FLAG_REG, 7
Before Instruction
FLAG_REG = 0xC7
After Instruction
FLAG_REG = 0x47
BSF Bit Set f
Syntax: [
label ] BSF f,b
Operands: 0 ≤ f ≤ 127
0 ≤ b ≤ 7
Operation: 1 → (f<b>)
Status Affected: None
Encoding:
01 01bb bfff ffff
Description:
Bit 'b' in register 'f' is set.
Words: 1
Cycles: 1
Q Cycle Activity: Q1 Q2 Q3 Q4
Decode Read
register
'f'
Process
data
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 ≤ 127
0 ≤ b ≤ 7
Operation: skip if (f<b>) = 0
Status Affected: None
Encoding:
01 10bb bfff ffff
Description:
If bit 'b' in register 'f' is '1' then the next
instruction is executed.
If bit 'b', in register 'f', is '0' then the next
instruction is discarded, and a NOP is
executed instead, making this a 2TCY
instruction
.
Words: 1
Cycles: 1(2)
Q Cycle Activity: Q1 Q2 Q3 Q4
Decode Read
register 'f'
Process
data
NOP
If Skip: (2nd Cycle)
Q1 Q2 Q3 Q4
NOP NOP NOP NOP
Example
HERE
FALSE
TRUE
BTFSC
GOTO
•
•
•
FLAG,1
PROCESS_CODE
Before Instruction
PC = address HERE
After Instruction
if FLAG<1> = 0,
PC = address TRUE
if FLAG<1>=1,
PC = address FALSE