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PHA: Difference between revisions

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'''PHA''' (PusH Accumulator) is a 65x instruction that pushes the value in the [[accumulator]] to the [[stack]].  If the accumulator is 16 bits wide, the high byte is pushed first.  The [[stack pointer]] is decremented.
'''PHA''' (PusH Accumulator) is a 65x instruction that pushes the value in the [[accumulator]] to the [[stack]].  If the accumulator is 16 bits wide, the high byte is pushed first.  The [[stack pointer]] is decremented by the number of bytes pushed.


No flags are affected.
No flags are affected.
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===== Cycle Penalty =====
==== Cycle Penalty ====
* PHA takes one extra cycle if the accumulator is 16 bits wide.
* PHA takes one extra cycle if the accumulator is 16 bits wide.


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* 8.5 on [[MCS6500 Manual]], [https://archive.org/details/mos_microcomputers_programming_manual/page/n136 page 117] on PHA
* 8.5 on [[MCS6500 Manual]], [https://archive.org/details/mos_microcomputers_programming_manual/page/n136 page 117] on PHA
* [[Carr]], [https://archive.org/details/6502UsersManual/page/n280 page 267] on PHA
* [[Carr]], [https://archive.org/details/6502UsersManual/page/n280 page 267] on PHA
* [[Leventhal]] page 3-81 on PHA: https://archive.org/details/6502-assembly-language-programming/page/n130
* [[Leventhal]], [https://archive.org/details/6502-assembly-language-programming/page/n130 page 3-81] on PHA


[[Category:ASM]]
[[Category:ASM]]

Latest revision as of 17:40, 23 August 2024

Basic Info
Addressing Mode Opcode Length Speed
Stack (Push) 48 1 byte 3 cycles*
Flags Affected
N V M X D I Z C
. . . . . . . .

PHA (PusH Accumulator) is a 65x instruction that pushes the value in the accumulator to the stack. If the accumulator is 16 bits wide, the high byte is pushed first. The stack pointer is decremented by the number of bytes pushed.

No flags are affected.

Syntax

PHA

Cycle Penalty

  • PHA takes one extra cycle if the accumulator is 16 bits wide.

See Also

External Links