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DAA (SPC700): Difference between revisions
From SnesLab
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'''DAA''' (Decimal Adjust for Addition) is an [[SPC700]] instruction. | '''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 === | ||
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* Official Super Nintendo development manual on DAA: [https://archive.org/details/SNESDevManual/book1/page/n233 Appendix C-8 of Book I] | * Official Super Nintendo development manual on DAA: [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 | * [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]] |
Revision as of 19:37, 22 July 2023
Basic Info | |||||||
---|---|---|---|---|---|---|---|
Addressing Mode | Opcode | Length | Speed | ||||
implied | DF | 1 byte | 3 cycles |
Flags Clobbered | |||||||
---|---|---|---|---|---|---|---|
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: Appendix C-8 of Book I
- page 3-8-2 of Book I lbid
- ares source code, SPC700::instructionDecimalAdjustAdd