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TCD: Difference between revisions
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'''TCD''' (Transfer aCcumulator to Direct page register) is a [[65c816]] instruction that transfers the value of the 16-bit [[accumulator]] to the [[direct page register]]. An alternate mnemonic is "TAD." | '''TCD''' (Transfer aCcumulator to Direct page register) is a [[65c816]] instruction that transfers the value of the 16-bit [[accumulator]] to the [[direct page register]]. An alternate mnemonic is "TAD." | ||
TCD ignores the | TCD ignores the [[m flag]]. If the accumulator is only 8 bits wide, the transfer still happens as if it were 16 bits wide. | ||
TCD works even in [[6502 emulation mode]]. | TCD works even in [[6502 emulation mode]]. | ||
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=== External Links === | === External Links === | ||
* [[Eyes & Lichty]] | * [[Eyes & Lichty]], [https://archive.org/details/0893037893ProgrammingThe65816/page/510 page 510] on TCD | ||
* [[Labiak]] | * [[Labiak]], [https://archive.org/details/Programming_the_65816/page/n201 page 191] on TCD | ||
* snes9x implementation of TCD: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L2320 | * snes9x implementation of TCD: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L2320 | ||
* Clark, Bruce. http://www.6502.org/tutorials/65c816opcodes.html#6.10.2 | * Clark, Bruce. http://www.6502.org/tutorials/65c816opcodes.html#6.10.2 | ||
Latest revision as of 23:19, 9 August 2024
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Implied (type 1) | 5B | 1 byte | 2 cycles | ||||
| Flags Affected | |||||||
|---|---|---|---|---|---|---|---|
| N | V | M | X | D | I | Z | C |
| N | . | . | . | . | . | Z | . |
TCD (Transfer aCcumulator to Direct page register) is a 65c816 instruction that transfers the value of the 16-bit accumulator to the direct page register. An alternate mnemonic is "TAD."
TCD ignores the m flag. If the accumulator is only 8 bits wide, the transfer still happens as if it were 16 bits wide.
TCD works even in 6502 emulation mode.
Syntax
TCD TAD
See Also
External Links
- Eyes & Lichty, page 510 on TCD
- Labiak, page 191 on TCD
- snes9x implementation of TCD: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L2320
- Clark, Bruce. http://www.6502.org/tutorials/65c816opcodes.html#6.10.2