Fujitsu CM71-00101-5E User Manual
79
CHAPTER 7 DETAILED EXECUTION INSTRUCTIONS
7.8
SUB (Subtract Word Data in Source Register from
Destination Register)
Destination Register)
Subtracts the word data in "Rj" from the word data in "Ri", stores results to "Ri".
■
SUB (Subtract Word Data in Source Register from Destination Register)
Assembler format:
SUB Rj, Ri
Operation:
Ri – Rj
→
Ri
Flag change:
N : Set when the MSB of the operation result is "1", cleared when the MSB is "0".
Z : Set when the operation result is "0", cleared otherwise.
V : Set when an overflow has occurred as a result of the operation, cleared otherwise.
C : Set when a borrow has occurred as a result of the operation, cleared otherwise.
Execution cycles:
1 cycle
Instruction format:
Example:
SUB R2, R3
N
Z
V
C
C
C
C
C
MSB
LSB
1
0
1
0
1
1
0
0
Rj
Ri
R2
R3
1 2 3 4
5 6 7 8
9 9 9 9
9 9 9 9
N Z V C
CCR
R2
R3
CCR
0 0 0 0
N Z V C
1 0 0 0
8 7 6 5
4 3 2 1
1 2 3 4
5 6 7 8
Before execution
After execution
Instruction bit pattern : 1010 1100 0010 0011