We've just updated MediaWiki and its underlying software. If anything doesn't look or work quite right, please mention it to us. --RanAS
WDM: Difference between revisions
From SnesLab
(official 65c816 datasheet says WDM is implied admode) |
(→External Links: page number) |
||
| Line 45: | Line 45: | ||
=== External Links === | === External Links === | ||
* [[Eyes & Lichty]] page on WDM: https://archive.org/details/0893037893ProgrammingThe65816/page/n549 | * [[Eyes & Lichty]] page 523, on WDM: https://archive.org/details/0893037893ProgrammingThe65816/page/n549 | ||
* snes9x implementation of WDM: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L3335 | * snes9x implementation of WDM: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L3335 | ||
* undisbeliever on WDM: https://undisbeliever.net/snesdev/65816-opcodes.html#wdm-reserved-for-future-expansion | * undisbeliever on WDM: https://undisbeliever.net/snesdev/65816-opcodes.html#wdm-reserved-for-future-expansion | ||
Revision as of 08:49, 20 November 2023
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Implied (type 3) | 42 | 2 byte | 2 cycles | ||||
| Flags Affected | |||||||
|---|---|---|---|---|---|---|---|
| N | V | M | X | D | I | Z | C |
| . | . | . | . | . | . | . | . |
WDM (the initials of William David Mensch, the designer of the 65c816) is an instruction that reserves its signature byte for future expansion of the instruction set. None of these extra 256 opcodes were ever implemented, so WDM functions essentially as a two-byte NOP.
Trivia
The Labiak textbook does not describe the WDM instruction.
See Also
External Links
- Eyes & Lichty page 523, on WDM: https://archive.org/details/0893037893ProgrammingThe65816/page/n549
- snes9x implementation of WDM: https://github.com/snes9xgit/snes9x/blob/master/cpuops.cpp#L3335
- undisbeliever on WDM: https://undisbeliever.net/snesdev/65816-opcodes.html#wdm-reserved-for-future-expansion