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TXA: Difference between revisions
From SnesLab
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|'''8-bit index registers (x=1)''' | |'''8-bit index registers (x=1)''' | ||
|8 bits are transferred | |8 bits are transferred | ||
|8 bits are transferred | |8 bits are transferred to the low byte of accumulator and high byte of the accumulator is zeroed | ||
|+ | |+ | ||
|'''16-bit index registers (x=0)''' | |'''16-bit index registers (x=0)''' | ||
Revision as of 05:00, 18 June 2023
TXA is a 65x instruction that transfers the value of the X index register to the accumulator.
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| implied | 8A | 1 byte | 2 cycles | ||||
| Flags Clobbered | |||||||
|---|---|---|---|---|---|---|---|
| N | V | M | X | D | I | Z | C |
| . | . | . | . | . | . | ||
| Instruction Behavior | ||
|---|---|---|
| 8-bit accumulator (m=1) | 16-bit accumulator (m=0) | |
| 8-bit index registers (x=1) | 8 bits are transferred | 8 bits are transferred to the low byte of accumulator and high byte of the accumulator is zeroed |
| 16-bit index registers (x=0) | 8 bits are transferred | 16 bits are transferred |
See Also
External Links
- Eyes & Lichty page on TXA: https://archive.org/details/0893037893ProgrammingThe65816/page/n543
- Labiak page on TXA: https://archive.org/details/Programming_the_65816/page/n208
- MCS6500 Manual page on TXA: https://archive.org/details/mos_microcomputers_programming_manual/page/n118
- Carr page on TXA: https://archive.org/details/6502UsersManual/page/n289
- Leventhal page on TXA: https://archive.org/details/6502-assembly-language-programming/page/n151
- snes9x implementation of TXA: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L2384