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CLD: Difference between revisions
From SnesLab
(→See Also: BRK) |
(→See Also: binary coded decimal) |
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'''CLD''' is a 65x instruction that clears the [[decimal mode flag]], switching the processor back into binary mode so [[ADC]] and [[SBC]] will operate normally. | '''CLD''' is a 65x instruction that clears the [[decimal mode flag]], switching the processor back into binary mode so [[ADC]] and [[SBC]] will operate normally. Hexadecimal digits A through F may appear in sums/differences. | ||
No other flags are affected. | No other flags are affected. | ||
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CLD | CLD | ||
</pre> | </pre> | ||
[[BRK]] handlers do not need CLD because BRK also clears the decimal flag. | |||
To clear more than one flag at the same time, use [[REP]]. | |||
=== See Also === | === See Also === | ||
* [[SED]] | * [[SED]] | ||
* [[CLC]] | * [[CLC]] | ||
* [[CLV]] | * [[CLV]] | ||
* [[ | * [[Binary Coded Decimal]] | ||
=== External Links === | === External Links === | ||
Latest revision as of 17:32, 20 September 2024
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Implied (type 2) | D8 | 1 byte | 2 cycles | ||||
| Flags Affected | ||||||||
|---|---|---|---|---|---|---|---|---|
| N | V | M | X | D | I | Z | C | |
| . | . | . | . | 0 | . | . | . | |
CLD is a 65x instruction that clears the decimal mode flag, switching the processor back into binary mode so ADC and SBC will operate normally. Hexadecimal digits A through F may appear in sums/differences.
No other flags are affected.
Syntax
CLD
BRK handlers do not need CLD because BRK also clears the decimal flag.
To clear more than one flag at the same time, use REP.
See Also
External Links
- Eyes & Lichty, page 442 on CLD
- Labiak, page 131 on CLD
- 3.3.2 on MCS6500 Manual, page 27 on CLD
- Carr, page 254 on CLD
- Leventhal, page 3-53 on CLD
- snes9x implementation of CLD: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1434
- Clark, Bruce. http://www.6502.org/tutorials/65c816opcodes.html#6.4.1