INSTRUCTION DESCRIPTIONS
A - 236 INSTRUCTION SET DETAILS
MOTOROLA
Operation: Assembler Syntax:
0–D
➞
D (parallel move) NEG D (parallel move)
Description:
Negate the destination operand D and store the result in the destination
accumulator. This is a 56-bit, twos-complement operation.
Example:
:
NEG B X1,X:(R3)+ Y:(R6)–,A ;0–B
➞
B, update A,X1,R3,R6
:
Explanation of Example:
Prior to execution, the 56-bit B accumulator contains the
value $00:123456:789ABC. The NEG B instruction takes the twos complement of the
value in the B accumulator and stores the 56-bit result back in the B accumulator.
Condition Codes:
S — Computed according to the definition in A.5 CONDITION CODE COMPUTATION
L — Set if limiting (parallel move) or overflow has occurred in result
E — Set if the signed integer portion of A or B result is in use
U — Set if A or B result is unnormalized
N — Set if bit 55 of A or B result is set
Z — Set if A or B result equals zero
V — Set if overflow has occurred in A or B result
Note:
The definitions of the E and U bits vary according to the scaling mode being used.
Refer to Section A.5 CONDITION CODE COMPUTATION for complete details.
NEG Negate Accumulator NEG
Before Execution After Execution
B$00:123456:789ABC $FF:EDCBA9:876544
B
MR CCR
1514131211109876543210
LF DM T ** S1 S0 I1 I0 SLEUNZVC