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REP: Difference between revisions
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{| class="wikitable" style="float:right;clear:right;width: | {| class="wikitable" style="float:right;clear:right;width:40%" | ||
!colspan="8"|Basic Info | !colspan="8"|Basic Info | ||
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|'''Speed''' | |'''Speed''' | ||
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| | |[[Immediate]] | ||
|C2 | |C2 | ||
|2 bytes | |2 bytes | ||
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|} | |} | ||
{| class="wikitable" style="float:right;clear:right;width: | {| class="wikitable" style="float:right;clear:right;width:40%" | ||
!colspan="9"|Flags | !colspan="9"|Flags Affected | ||
|+ | |+ | ||
|N | | | ||
|V | |[[Negative Flag|N]] | ||
|M | |[[Overflow Flag|V]] | ||
|X | |[[M Flag|M]] | ||
|D | |[[X Flag|X]] | ||
|I | |[[Decimal Flag|D]] | ||
|Z | |[[I Flag|I]] | ||
|C | |[[Zero Flag|Z]] | ||
|[[Carry Flag|C]] | |||
|+ | |+ | ||
| [[emulation mode]] | |||
| | |||
| | |||
|. | |||
|. | |||
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| | |||
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|+ | |||
| [[native mode]] | |||
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|} | |} | ||
'''REP''' is a [[65c816]] instruction that clears bits in the [[status register]] that correspond to set bits in the operand. | '''REP''' (Reset Status Bits) is a [[65c816]] instruction that clears bits in the [[status register]] that correspond to set bits in the operand. | ||
REP appears to be the only way to clear the m and x flags other than [[PLP]] and [[RTI]]. | |||
=== See Also === | === See Also === | ||
* [[SEP]] | * [[SEP]] | ||
* [[CLC]] | |||
* [[CLV]] | |||
* [[CLD]] | |||
* [[CLI]] | |||
=== External Links === | === External Links === | ||
* [[Eyes & Lichty]] page on REP: https://archive.org/details/0893037893ProgrammingThe65816/page/n515 | * [[Eyes & Lichty]] page 489, on REP: https://archive.org/details/0893037893ProgrammingThe65816/page/n515 | ||
* [[Labiak]] page on REP: https://archive.org/details/Programming_the_65816/page/n183 | * [[Labiak]] page 173 on REP: https://archive.org/details/Programming_the_65816/page/n183 | ||
* snes9x implementation of REP: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L3145 | * snes9x implementation of REP: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L3145 | ||
* undisbeliever on REP: https://undisbeliever.net/snesdev/65816-opcodes.html#rep-reset-status-bits | * undisbeliever on REP: https://undisbeliever.net/snesdev/65816-opcodes.html#rep-reset-status-bits | ||
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[[Category:ASM]] | [[Category:ASM]] | ||
[[Category:65c816 additions]] | [[Category:65c816 additions]] | ||
[[Category:Two-byte Instructions]] | |||
[[Category:Three-cycle Instructions]] | |||
[[Category:Single Admode Mnemonics]] | |||
Latest revision as of 16:52, 14 December 2023
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Immediate | C2 | 2 bytes | 3 cycles | ||||
| Flags Affected | ||||||||
|---|---|---|---|---|---|---|---|---|
| N | V | M | X | D | I | Z | C | |
| emulation mode | . | . | ||||||
| native mode | ||||||||
REP (Reset Status Bits) is a 65c816 instruction that clears bits in the status register that correspond to set bits in the operand.
REP appears to be the only way to clear the m and x flags other than PLP and RTI.
See Also
External Links
- Eyes & Lichty page 489, on REP: https://archive.org/details/0893037893ProgrammingThe65816/page/n515
- Labiak page 173 on REP: https://archive.org/details/Programming_the_65816/page/n183
- snes9x implementation of REP: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L3145
- undisbeliever on REP: https://undisbeliever.net/snesdev/65816-opcodes.html#rep-reset-status-bits