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DAS (SPC700): Difference between revisions

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=== External Links ===
=== External Links ===
* Official Super Nintendo development manual on DAS: [https://archive.org/details/SNESDevManual/book1/page/n233 Appendix C-8 of Book I]
* Official Super Nintendo development manual on DAS: 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
* [https://archive.org/details/SNESDevManual/book1/page/n180 page 3-8-2 of Book I], lbid
* ares source code, SPC700::instructionDecimalAdjustSub
* ares source code, SPC700::instructionDecimalAdjustSub

Revision as of 10:05, 20 November 2023

Basic Info
Addressing Mode Opcode Length Speed
Accumulator BE 1 byte 3 cycles
Flags Clobbered
N V P B H I Z C
. . . . .

DAS (Decimal Adjust for Subtraction) is an SPC700 instruction that performs the following:

  1. If either the carry flag is clear or the accumulator exceeds 0x99, 0x60 is subtracted from the accumulator and the carry flag is cleared.
  2. Then, if either the half-carry flag is clear or the low nibble of the accumulator exceeds 0x09, 0x06 is subtracted from the accumulator

See Also

External Links