Datasheet

Table Of Contents
2002 Microchip Technology Inc. Preliminary DS40044A-page 115
PIC16F627A/628A/648A
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 instruc-
tion fetched during the current
instruction execution, is discarded
and a NOP is executed instead,
making this a two-cycle instruc-
tion.
Words: 1
Cycles: 1(2)
Example
HERE
FALSE
TRUE
BTFSS
GOTO
REG1
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 imme-
diate 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 REG1
Before Instruction
REG1 = 0x5A
After Instruction
REG1 = 0x00
Z=1