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CLC: Difference between revisions
From SnesLab
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* [[MCS6500 Manual]] page 25 on CLC: https://archive.org/details/mos_microcomputers_programming_manual/page/n40 | * [[MCS6500 Manual]] page 25 on CLC: https://archive.org/details/mos_microcomputers_programming_manual/page/n40 | ||
* [[Carr]], [https://archive.org/details/6502UsersManual/page/n266 page 253] on CLC | * [[Carr]], [https://archive.org/details/6502UsersManual/page/n266 page 253] on CLC | ||
* [[Leventhal]] | * [[Leventhal]], [https://archive.org/details/6502-assembly-language-programming/page/n101 page 3-52] on CLC | ||
* snes9x implementation of CLC: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1420 | * snes9x implementation of CLC: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1420 | ||
* Clark, Bruce. http://www.6502.org/tutorials/65c816opcodes.html#6.4.1 | * Clark, Bruce. http://www.6502.org/tutorials/65c816opcodes.html#6.4.1 | ||
Revision as of 03:15, 8 August 2024
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Implied (type 2) | 18 | 1 byte | 2 cycles | ||||
| Flags Affected | ||||||||
|---|---|---|---|---|---|---|---|---|
| N | V | M | X | D | I | Z | C | |
| . | . | . | . | . | . | . | 0 | |
CLC is a 65x instruction that clears the carry flag.
The 6502 lacks an add-without-carry instruction, so it is important to make sure the carry flag is clear before doing an ADC or else the sum will be one too great.
Syntax
CLC
One of the first instructions a SNES game runs after coming out of reset is often a CLC so that XCE can switch to native mode.
See Also
External Links
- Eyes & Lichty, page 441 on CLC
- Labiak, page 130 on CLC
- MCS6500 Manual page 25 on CLC: https://archive.org/details/mos_microcomputers_programming_manual/page/n40
- Carr, page 253 on CLC
- Leventhal, page 3-52 on CLC
- snes9x implementation of CLC: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L1420
- Clark, Bruce. http://www.6502.org/tutorials/65c816opcodes.html#6.4.1