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CLC: Difference between revisions
From SnesLab
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=== External Links === | === External Links === | ||
* [[Eyes & Lichty]] page 441, on CLC: https://archive.org/details/0893037893ProgrammingThe65816/page/441 | * [[Eyes & Lichty]] page 441, on CLC: https://archive.org/details/0893037893ProgrammingThe65816/page/441 | ||
* [[Labiak]] | * [[Labiak]], [https://archive.org/details/Programming_the_65816/page/n140 page 130] on CLC | ||
* [[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]] page 253 on CLC: https://archive.org/details/6502UsersManual/page/n266 | * [[Carr]] page 253 on CLC: https://archive.org/details/6502UsersManual/page/n266 | ||
Revision as of 13:25, 6 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: https://archive.org/details/0893037893ProgrammingThe65816/page/441
- 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: https://archive.org/details/6502UsersManual/page/n266
- Leventhal page 3-52 on CLC: https://archive.org/details/6502-assembly-language-programming/page/n101
- 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