Datasheet

PIC17C7XX
DS30289C-page 206  1998-2013 Microchip Technology Inc.
BTFSS Bit Test, skip if Set
Syntax: [ label ] BTFSS f,b
Operands: 0  f  127
0  b < 7
Operation: skip if (f<b>) = 1
Status Affected: None
Encoding:
1001 0bbb ffff ffff
Description:
If bit 'b' in register 'f' is 1, then the next
instruction is skipped.
If bit 'b' is 1, then the next instruction
fetched during the current instruction exe-
cution is discarded and a NOP is executed
instead, making this a two-cycle
instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register 'f'
Process
Data
No
operation
If skip:
Q1 Q2 Q3 Q4
No
operation
No
operation
No
operation
No
operation
Example:
HERE
FALSE
TRUE
BTFSS
:
:
FLAG,1
Before Instruction
PC = address (HERE)
After Instruction
If FLAG<1> = 0;
PC = address (FALSE)
If FLAG<1> = 1;
PC = address (TRUE)
BTG Bit Toggle f
Syntax: [ label ] BTG f,b
Operands: 0  f  255
0  b < 7
Operation: (f<b>
)  (f<b>)
Status Affected: None
Encoding:
0011 1bbb ffff ffff
Description:
Bit 'b' in data memory location 'f' is
inverted.
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register 'f'
Process
Data
Write
register 'f'
Example:
BTG PORTC, 4
Before Instruction:
PORTC = 0111 0101 [0x75]
After Instruction:
PORTC = 0110 0101 [0x65]