Datasheet

© 2007 Microchip Technology Inc. DS39599G-page 265
PIC18F2220/2320/4220/4320
ANDWF AND W with f
Syntax: [ label ] ANDWF f [,d [,a]]
Operands: 0 ≤ f ≤ 255
d ∈ [0,1]
a ∈ [0,1]
Operation: (W) .AND. (f) → dest
Status Affected: N, Z
Encoding:
0001 01da ffff ffff
Description: The contents of W are AND’ed with
register ‘f’. If ‘d’ is ‘0’, the result is
stored in W. If ‘d’ is ‘1’, the result is
stored back in register ‘f’ (default).
If ‘a’ is ‘0’, the Access Bank will be
selected. If ‘a’ is ‘1’, the BSR will
not be overridden (default).
Words: 1
Cycles: 1
Q Cycle Activity:
Q1 Q2 Q3 Q4
Decode Read
register ‘f’
Process
Data
Write to
destination
Example:
ANDWF REG, W
Before Instruction
W = 0x17
REG = 0xC2
After Instruction
W = 0x02
REG = 0xC2
BC Branch if Carry
Syntax: [ label ] BC n
Operands: -128 ≤ n ≤ 127
Operation: if Carry bit is ‘1’,
(PC) + 2 + 2n → PC
Status Affected: None
Encoding:
1110 0010 nnnn nnnn
Description: If the Carry bit is ‘1’, then the
program will branch.
The 2’s complement number ‘2n’ is
added to the PC. Since the PC will
have incremented to fetch the next
instruction, the new address will be
PC + 2 + 2n. This instruction is
then a two-cycle instruction.
Words: 1
Cycles: 1(2)
Q Cycle Activity:
If Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
Write to PC
No
operation
No
operation
No
operation
No
operation
If No Jump:
Q1 Q2 Q3 Q4
Decode Read literal
‘n’
Process
Data
No
operation
Example:
HERE BC JUMP
Before Instruction
PC = address (HERE)
After Instruction
If Carry = 1;
PC = address (JUMP)
If Carry = 0;
PC = address (HERE + 2)