PIC18F2480/2580/4480/4580
CPFSGT
Compare f with W, Skip if f > W
CPFSLT
Compare f with W, Skip if f < W
Syntax:
CPFSGT f {,a}
Syntax:
CPFSLT f {,a}
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operands:
0 ≤ f ≤ 255
a ∈ [0,1]
Operation:
(f) − (W),
skip if (f) > (W)
(unsigned comparison)
Operation:
(f) – (W),
skip if (f) < (W)
(unsigned comparison)
Status Affected:
Encoding:
None
Status Affected:
Encoding:
None
0110
010a
ffff
ffff
0110
000a
ffff
ffff
Description:
Compares the contents of data memory
location ‘f’ to the contents of the W by
performing an unsigned subtraction.
Description:
Compares the contents of data memory
location ‘f’ to the contents of W by
performing an unsigned subtraction.
If the contents of ‘f’ are greater than the
contents of WREG, then the fetched
instruction is discarded and a NOPis
executed instead, making this a
two-cycle instruction.
If the contents of ‘f’ are less than the
contents of W, then the fetched
instruction is discarded and a NOPis
executed instead, making this a
two-cycle instruction.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’, the Access Bank is selected.
If ‘a’ is ‘1’, the BSR is used to select the
GPR bank.
If ‘a’ is ‘0’ and the extended instruction
set is enabled, this instruction operates
in Indexed Literal Offset Addressing
mode whenever f ≤ 95 (5Fh). See
Section 26.2.3 “Byte-Oriented and
Bit-Oriented Instructions in Indexed
Literal Offset Mode” for details.
Words:
Cycles:
1
1(2)
Note: 3 cycles if skip and followed
by a 2-word instruction.
Q Cycle Activity:
Q1
Q2
Q3
Q4
Words:
Cycles:
1
Decode
Read
register ‘f’
Process
Data
No
operation
1(2)
Note: 3 cycles if skip and followed
If skip:
Q1
by a 2-word instruction.
Q2
Q3
Q4
Q Cycle Activity:
Q1
No
operation
No
operation
No
operation
No
operation
Q2
Read
Q3
Process
Data
Q4
No
operation
Decode
If skip and followed by 2-word instruction:
register ‘f’
If skip:
Q1
Q2
Q3
Q4
Q1
No
Q2
No
Q3
No
Q4
No
No
operation
No
operation
No
operation
No
operation
operation
operation
operation
operation
No
No
No
No
If skip and followed by 2-word instruction:
operation
operation
operation
operation
Q1
No
operation
No
Q2
No
operation
No
Q3
No
operation
No
Q4
No
operation
No
Example:
HERE
NLESS
LESS
CPFSLT REG, 1
:
:
operation
operation
operation
operation
Before Instruction
PC
W
=
=
Address (HERE)
Example:
HERE
NGREATER
GREATER
CPFSGT REG, 0
:
:
?
After Instruction
If REG
PC
If REG
PC
<
=
≥
=
W;
Address (LESS)
W;
Before Instruction
PC
W
=
=
Address (HERE)
Address (NLESS)
?
After Instruction
If REG
PC
If REG
PC
>
=
≤
=
W;
Address (GREATER)
W;
Address (NGREATER)
© 2009 Microchip Technology Inc.
DS39637D-page 385
MICROCHIP [ MICROCHIP ]
