CPU12
INSTRUCTION GLOSSARY
MOTOROLA
REFERENCE MANUAL
6-157
Operation:
(SP) – $0002
⇒
SP
(A : B)
⇒
M
(SP)
: M
(SP
+
1)
Description:
Stacks the content of double accumulator D. The stack pointer is decre-
mented by two, then the contents of accumulators A and B are stacked
at the location to which the SP points.
After PSHD executes, the SP points to the stacked value of accumulator
A. This stacking order is the opposite of the order in which A and B are
stacked when an interrupt is recognized. The interrupt stacking order is
backward-compatible with the M6800, which had no 16-bit accumulator.
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:
None affected.
Addressing Modes, Machine Code, and Execution Times:
PSHD
Push Double Accumulator onto Stack
PSHD
S
X
H
I
N
Z
V
C
–
–
–
–
–
–
–
–
Source Form
Address Mode
Object Code
Cycles
Access Detail
PSHD
INH
3B
2
OS
Summary of Contents for CPU12
Page 8: ...MOTOROLA CPU12 viii REFERENCE MANUAL ...
Page 14: ...MOTOROLA INTRODUCTION CPU12 1 4 REFERENCE MANUAL ...
Page 20: ...MOTOROLA OVERVIEW CPU12 2 6 REFERENCE MANUAL ...
Page 38: ...MOTOROLA INSTRUCTION QUEUE CPU12 4 6 REFERENCE MANUAL ...
Page 300: ...MOTOROLA DEVELOPMENT AND DEBUG SUPPORT CPU12 8 16 REFERENCE MANUAL ...
Page 338: ...MOTOROLA MEMORY EXPANSION CPU12 10 8 REFERENCE MANUAL ...
Page 364: ...MOTOROLA INSTRUCTION REFERENCE CPU12 A 26 REFERENCE MANUAL ...
Page 386: ...MOTOROLA HIGH LEVEL LANGUAGE SUPPORT CPU12 C 6 REFERENCE MANUAL ...
Page 438: ...MOTOROLA SUMMARY OF CHANGES CPU12 S 2 REFERENCE MANUAL ...
Page 439: ......