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DAA (SPC700): Difference between revisions
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!colspan="8"|Basic Info | !colspan="8"|Basic Info | ||
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|'''Speed''' | |'''Speed''' | ||
|+ | |+ | ||
| | |[[Accumulator Addressing | Accumulator]] | ||
|DF | |DF | ||
|1 byte | |1 byte | ||
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!colspan="8"|Flags | !colspan="8"|Flags Affected | ||
|+ | |+ | ||
|N | |[[Negative Flag|N]] | ||
|V | |[[Overflow Flag|V]] | ||
|P | |[[Direct Page Flag|P]] | ||
|B | |[[Break Flag|B]] | ||
|H | |[[Half-Carry Flag|H]] | ||
|I | |[[Interrupt Enable Flag|I]] | ||
|Z | |[[Zero Flag|Z]] | ||
|C | |[[Carry Flag|C]] | ||
|+ | |+ | ||
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|} | |} | ||
'''DAA''' (Decimal Adjust for Addition) is an [[SPC700]] instruction that performs the following: | |||
# If either the [[carry flag]] is set or the [[accumulator]] exceeds 0x99, 0x60 is added to the accumulator and the carry flag is set. | |||
# Then, if either the [[half-carry flag]] is set, or the lower nibble of the accumulator exceeds 0x09, 0x06 is added to the accumulator. | |||
=== See Also === | === See Also === | ||
* [[DAS]] | * [[DAS]] | ||
* [[BCD]] | * [[BCD]] | ||
=== External Links === | |||
* Official Super Nintendo development manual on DAA: Table C-14 in [https://archive.org/details/SNESDevManual/book1/page/n233 Appendix C-8 of Book I] | |||
* [https://archive.org/details/SNESDevManual/book1/page/n180 page 3-8-2 of Book I] lbid | |||
* ares source code, SPC700::instructionDecimalAdjustAdd | |||
[[Category:ASM]] | [[Category:ASM]] | ||
[[Category:SPC700]] | [[Category:SPC700]] | ||
[[Category:Decimal Compensation Commands]] | [[Category:Decimal Compensation Commands]] |
Latest revision as of 05:03, 27 November 2023
Basic Info | |||||||
---|---|---|---|---|---|---|---|
Addressing Mode | Opcode | Length | Speed | ||||
Accumulator | DF | 1 byte | 3 cycles |
Flags Affected | |||||||
---|---|---|---|---|---|---|---|
N | V | P | B | H | I | Z | C |
. | . | . | . | . |
DAA (Decimal Adjust for Addition) is an SPC700 instruction that performs the following:
- If either the carry flag is set or the accumulator exceeds 0x99, 0x60 is added to the accumulator and the carry flag is set.
- Then, if either the half-carry flag is set, or the lower nibble of the accumulator exceeds 0x09, 0x06 is added to the accumulator.
See Also
External Links
- Official Super Nintendo development manual on DAA: Table C-14 in Appendix C-8 of Book I
- page 3-8-2 of Book I lbid
- ares source code, SPC700::instructionDecimalAdjustAdd