Datasheet

 1996 Microchip Technology Inc. Preliminary DS40122B-page 101
PIC14000
SUBLW Subtract W from Literal
Syntax: [
label ] SUBLW k
Operands: 0 ≤ k ≤ 255
Operation: k - (W) → (W)
Status
Affected:
C, DC, Z
Encoding: 11 110x kkkk kkkk
Description:
The W register is subtracted (2’s com-
plement method) from the eight bit literal
'k'. The result is placed in the W register.
Words: 1
Cycles: 1
Example 1: SUBLW 0x02
Before Instruction
W= 1
C=?
After Instruction
W= 1
C = 1; result is positive
Example 2: Before Instruction
W= 2
C=?
After Instruction
W= 0
C = 1; result is zero
Example 3: Before Instruction
W= 3
C=?
After Instruction
W = 0xFF
C = 0; result is nega-
tive
SUBWF Subtract W from f
Syntax: [
label ] SUBWF f,d
Operands: 0 ≤ f ≤ 127
d ∈ [0,1]
Operation: (f) - (W) → (dest)
Status
Affected:
C, DC, Z
Encoding: 00 0010 dfff ffff
Description:
Subtract (2’s complement method) W reg-
ister from register 'f'. If 'd' is 0 the result is
stored in the W register. If 'd' is 1 the
result is stored back in register 'f'.
Words: 1
Cycles: 1
Example 1: SUBWF REG1,1
Before Instruction
REG1 = 3
W=2
C=?
After Instruction
REG1 = 1
W=2
C = 1; result is positive
Example 2: Before Instruction
REG1 = 2
W=2
C=?
After Instruction
REG1 = 0
W=2
C = 1; result is zero
Example 3: Before Instruction
REG1 = 1
W=2
C=?
After Instruction
REG1 = 0xFF
W=2
C = 0; result is negative