PIC17C4X Datasheet, PDF (116/240 Pages) Microchip Technology – High-Performance 8-Bit CMOS EPROM/ROM Microcontroller

PIC17C4X
BTFSS
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
Q1
Decode
If skip:
Q1
Forced NOP
Bit Test, skip if Set
[ label ] BTFSS f,b
0 ≤ f ≤ 127
0≤b<7
skip if (f<b>) = 1
None
1001 0bbb ffff ffff
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 an NOP is exe-
cuted instead, making this a two-cycle
instruction.
1
1(2)
Q2
Read
register 'f'
Q3
Execute
Q2
NOP
Q3
Execute
Q4
NOP
Q4
NOP
Example:
HERE
FALSE
TRUE
BTFSS
:
:
FLAG,1
Before Instruction
PC
= address (HERE)
After Instruction
If FLAG<1> =
PC
=
If FLAG<1> =
PC
=
0;
address (FALSE)
1;
address (TRUE)
BTG
Syntax:
Operands:
Operation:
Status Affected:
Encoding:
Description:
Words:
Cycles:
Q Cycle Activity:
Q1
Decode
Bit Toggle f
[ label ] BTG f,b
0 ≤ f ≤ 255
0≤b<7
(f<b>) → (f<b>)
None
0011 1bbb ffff ffff
Bit 'b' in data memory location 'f' is
inverted.
1
1
Q2
Read
register 'f'
Q3
Execute
Q4
Write
register 'f'
Example:
BTG
PORTC, 4
Before Instruction:
PORTC = 0111 0101 [0x75]
After Instruction:
PORTC = 0110 0101 [0x65]
DS30412C-page 116
© 1996 Microchip Technology Inc.