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SBA
(A) – (B) ⇒ A
Operation:
Description:
Subtracts the content of accumulator B from the content of accumulator
A and places the result in A. The content of B is not affected. For sub-
traction instructions, the C status bit represents a borrow.
Condition Codes and Boolean Formulas:
S
–
N:
Z:
V:
C:
Addressing Modes, Machine Code, and Execution Times:
Source Form
SBA
CPU12
REFERENCE MANUAL
Subtract Accumulators
X
H
I
N
Z
∆
∆
–
–
–
Set if MSB of result is set; cleared otherwise.
Set if result is $00; cleared otherwise.
A7 • B7 • R7 + A7 • B7 • R7
Set if a two's complement overflow resulted from the operation;
cleared otherwise.
A7 • B7 + B7 • R7 + R7 • A7
Set if the absolute value of B is larger than the absolute value of A;
cleared otherwise.
Address Mode
INH
INSTRUCTION GLOSSARY
V
C
∆
∆
Object Code
18 16
SBA
Cycles
Access Detail
2
OO
MOTOROLA
6-179
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