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PSHA
(SP) – $0001 ⇒ SP
Operation:
(A) ⇒ M
Description:
Stacks the content of accumulator A. The stack pointer is decremented
by one. The content of A is then stacked at the address the SP points to.
Push instructions are commonly used to save the contents of one or
more CPU registers at the start of a subroutine. Complementary pull in-
structions can be used to restore the saved CPU registers just before re-
turning from the subroutine.
Condition Codes and Boolean Formulas:
S
–
None affected.
Addressing Modes, Machine Code, and Execution Times:
Source Form
PSHA
MOTOROLA
6-154
Push A onto Stack
(SP)
X
H
I
N
Z
–
–
–
–
–
Address Mode
INH
36
INSTRUCTION GLOSSARY
V
C
–
–
Object Code
PSHA
Cycles
Access Detail
2
Os
CPU12
REFERENCE MANUAL
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