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Useful Code Snippets: Difference between revisions
From SnesLab
Vitor Vilela (talk | contribs) |
Vitor Vilela (talk | contribs) |
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=== Unsigned 16 bit x 16 bit = 32 bit multiplication === | === Unsigned 16 bit x 16 bit = 32 bit multiplication === | ||
by [[User:Akaginite | by [[User:Akaginite|Akaginite]] | ||
<pre> | <pre> | ||
Revision as of 01:07, 26 July 2019
Useful code snippets for the 65c816 ASM and general SNES hardware.
65c816 S-CPU
Wait for H-Blank
- BIT $4212 BVS - - BIT $4212 BVC -
65c816 SA-1 CPU
Unsigned 16 bit x 16 bit = 32 bit multiplication
by Akaginite
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; 16bit * 16bit Multiplication SA-1 version ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; ; Argusment ; $00-$01 : Multiplicand ; $02-$03 : Multiplier ; Return values ; $04-$07 : Product ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; MathMul16_16: STZ $2250 REP #$20 LDA $00 STA $2251 ASL A LDA $02 STA $2253 BCS + LDA.w #$0000 + BIT $02 BPL + CLC ADC $00 + CLC ADC $2308 STA $06 LDA $2306 STA $04 SEP #$20 RTS