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PSHX
(SP) – $0002 ⇒ SP
Operation:
(X
H
Description:
Stacks the content of index register X. The stack pointer is decremented
by two. The content of X is then stacked at the address to which the SP
points. After PSHX executes, the SP points to the stacked value of the
high-order half of X.
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
PSHX
MOTOROLA
6-158
Push Index Register X onto Stack
) ⇒ M
: X
: M
(SP + 1)
L
(SP)
X
H
I
N
Z
–
–
–
–
–
Address Mode
INH
INSTRUCTION GLOSSARY
V
C
–
–
Object Code
34
PSHX
Cycles
Access Detail
2
OS
CPU12
REFERENCE MANUAL
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