We've just updated MediaWiki and its underlying software. If anything doesn't look or work quite right, please mention it to us. --RanAS
DAS (SPC700): Difference between revisions
From SnesLab
(added syntax) |
(→Syntax: added DAS A) |
||
| Line 42: | Line 42: | ||
<pre> | <pre> | ||
DAS | DAS | ||
DAS A | |||
</pre> | </pre> | ||
Revision as of 20:47, 6 July 2024
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Accumulator | BE | 1 byte | 3 cycles | ||||
| Flags Affected | |||||||
|---|---|---|---|---|---|---|---|
| N | V | P | B | H | I | Z | C |
| . | . | . | . | . | |||
DAS (Decimal Adjust for Subtraction) is an SPC700 instruction that performs the following:
- If either the carry flag is clear or the accumulator exceeds 0x99, subtract 0x60 from the accumulator and clear the carry flag.
- Then, if either the half-carry flag is clear or the low nibble of the accumulator exceeds 0x09, subtract 0x06 from the accumulator.
Syntax
DAS DAS A
See Also
External Links
- Official Super Nintendo development manual on DAS: Table C-14 in Appendix C-8 of Book I
- page 3-8-2 of Book I, lbid
- ares source code, SPC700::instructionDecimalAdjustSub