Datasheet

 1996 Microchip Technology Inc. Preliminary DS40122B-page 95
PIC14000
BTFSS Bit Test f, 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:
01 11bb bfff 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
execution, is discarded and a NOP is
executed instead, making this a 2 cycle
instruction.
Words: 1
Cycles: 1(2)
Example
HERE
FALSE
TRUE
BTFSC
GOTO
•
•
•
FLAG,1
PROCESS_CODE
Before Instruction
PC = address HERE
After Instruction
if FLAG<1> = 0,
PC = address FALSE
if FLAG<1> = 1,
PC = address TRUE
CALL Call Subroutine
Syntax: [
label ] CALL k
Operands: 0 ≤ k ≤ 2047
Operation: (PC)+ 1→ TOS,
k → PC<10:0>,
(PCLATH<4:3>) → PC<12:11>
Status Affected: None
Encoding:
10 0kkk kkkk kkkk
Description:
Call Subroutine. First, return address
(PC+1) is pushed onto the stack. The
eleven bit immediate address is loaded
into PC bits <10:0>. The upper bits of
the PC are loaded from PCLATH.
CALL is a two cycle instruction.
Words: 1
Cycles: 2
Example
HERE CALL THERE
Before Instruction
PC = Address HERE
After Instruction
PC = Address THERE
TOS = Address HERE+1
CLRF Clear f
Syntax: [
label ] CLRF f
Operands: 0 ≤ f ≤ 127
Operation: 00h → (f)
1 → Z
Status Affected: Z
Encoding:
00 0001 1fff ffff
Description:
The contents of register 'f' are cleared
and the Z bit is set.
Words: 1
Cycles: 1
Example
CLRF FLAG_REG
Before Instruction
FLAG_REG = 0x5A
After Instruction
FLAG_REG = 0x00
Z=1
CLRW Clear W
Syntax: [
label ] CLRW
Operands: None
Operation: 00h → (W)
1 → Z
Status Affected: Z
Encoding:
00 0001 0xxx xxxx
Description:
W register is cleared. Zero bit (Z) is
set.
Words: 1
Cycles: 1
Example
CLRW
Before Instruction
W = 0x5A
After Instruction
W = 0x00
Z=1