SPU transfer control
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p1 = mode?
0: tell SPU to start DMA read transfer
1: tell SPU to stop data transfer
2: give p2 instruction to SPU control
3: execute sound data transfer
p2 = spu control instruction << 3 // if p1 = 3, memory address to read sound data from
p3 = size (bytes) of area to transfer
p4 = not used
00018e44: afa40000 sw r4,0x0000(r29) # goes to stack.18 00018e48: afa50004 sw r5,0x0004(r29) # stack.1c 00018e4c: afa60008 sw r6,0x0008(r29) # stack.20 00018e50: afa7000c sw r7,0x000c(r29) # stack.24 ? weird ass stack management. 00018e54: 27bdffe8 addiu r29,r29,0xffe8 # - 0x18 00018e58: afb00010 sw r16,0x0010(r29) 00018e5c: 27b0001c addiu r16,r29,0x001c 00018e60: 34060001 ori r6,r0,0x0001 00018e64: afbf0014 sw r31,0x0014(r29) 00018e68: 1086001a beq r4,r6,0x00018ed4 # branch if p1 = 1 00018e6c: afa40018 sw r4,0x0018(r29) # save p1 over itself 00018e70: 28820002 slti r2,r4,0x0002 00018e74: 10400005 beq r2,r0,0x00018e8c # branch if p1 > 1 00018e78: 00000000 nop 00018e7c: 10800031 beq r4,r0,0x00018f44 # branch if p1 = 0 00018e80: 00001021 addu r2,r0,r0 00018e84: 08006430 j 0x000190c0 00018e88: 00000000 nop
00018e8c: 34020002 ori r2,r0,0x0002 00018e90: 10820005 beq r4,r2,0x00018ea8 # branch if p1 = 2 00018e94: 34020003 ori r2,r0,0x0003 00018e98: 10820045 beq r4,r2,0x00018fb0 # branch if p1 = 3 00018e9c: 00001021 addu r2,r0,r0 00018ea0: 08006430 j 0x000190c0 # else end return 0 00018ea4: 00000000 nop
p1 = 2 (give p2 instruction >> 3 to sound data transfer?)
00018ea8: 8fa4001c lw r4,0x001c(r29) # p2 00018eac: 3c028003 lui r2,0x8003 00018eb0: 8c42ad6c lw r2,-0x5294(r2) # 3 00018eb4: 3c038003 lui r3,0x8003 00018eb8: 8c63ad44 lw r3,-0x52bc(r3) # SPU IO left port address 00018ebc: 00441006 srlv r2,r4,r2 # p2 >> 3 (?) 00018ec0: 3c018003 lui r1,0x8003 00018ec4: a422ad5c sh r2,-0x52a4(r1) # store current instruction to RAM 00018ec8: a46201a6 sh r2,0x01a6(r3) # store instruction in sound data transfer address 00018ecc: 08006430 j 0x000190c0 # return 0 00018ed0: 00001021 addu r2,r0,r0
p1 = 1 (tell SPU to stop data transfer)
00018ed4: 3c058003 lui r5,0x8003 00018ed8: 8ca5ad44 lw r5,-0x52bc(r5) # SPU IO port left 00018edc: 3c048003 lui r4,0x8003 00018ee0: 9484ad5c lhu r4,-0x52a4(r4) # current spu data transfer instruction 00018ee4: 94a201a6 lhu r2,0x01a6(r5) # read from sound data transfer address 00018ee8: 3c018003 lui r1,0x8003 00018eec: ac20ad94 sw r0,-0x526c(r1) # set dma not reading? 00018ef0: 3042ffff andi r2,r2,0xffff # sound buffer address/8 00018ef4: 10440009 beq r2,r4,0x00018f1c # branch if instruction = instruction in port 00018ef8: 00001821 addu r3,r0,r0
sound data transfer instruction != instruction in port 00018efc: 24630001 addiu r3,r3,0x0001 00018f00: 2c620f01 sltiu r2,r3,0x0f01 00018f04: 1040006e beq r2,r0,0x000190c0 # branch if timed out? 00018f08: 2402fffe addiu r2,r0,0xfffe # return -2 00018f0c: 94a201a6 lhu r2,0x01a6(r5) # read from sound data transfer address 00018f10: 00000000 nop 00018f14: 1444fffa bne r2,r4,0x00018f00 # loop if not 0 00018f18: 24630001 addiu r3,r3,0x0001 # i ++
sound data transfer instruction == instruction in port 00018f1c: 3c038003 lui r3,0x8003 00018f20: 8c63ad44 lw r3,-0x52bc(r3) # SPU IO port left 00018f24: 00000000 nop 00018f28: 946401aa lhu r4,0x01aa(r3) # read SPU control register 00018f2c: 00000000 nop 00018f30: 3082ffcf andi r2,r4,0xffcf # stop sound transfer 00018f34: 34440020 ori r4,r2,0x0020 00018f38: a46401aa sh r4,0x01aa(r3) # tell SPU to stop sound transfer 00018f3c: 08006430 j 0x000190c0 # end return 0 00018f40: 00001021 addu r2,r0,r0
p1 = 0 (tell SPU to start DMA read transfer)
00018f44: 3c058003 lui r5,0x8003 00018f48: 8ca5ad44 lw r5,-0x52bc(r5) # SPU IO port left 00018f4c: 3c048003 lui r4,0x8003 00018f50: 9484ad5c lhu r4,-0x52a4(r4) # SPU data transfer instruction 00018f54: 94a201a6 lhu r2,0x01a6(r5) # read from SPU data transfer address 00018f58: 3c018003 lui r1,0x8003 00018f5c: ac26ad94 sw r6,-0x526c(r1) # store dma reading? 00018f60: 3042ffff andi r2,r2,0xffff 00018f64: 10440009 beq r2,r4,0x00018f8c # branch if instruction in RAM == instruction in port 00018f68: 00001821 addu r3,r0,r0
instruction in port != instruction in RAM 00018f6c: 24630001 addiu r3,r3,0x0001 00018f70: 2c620f01 sltiu r2,r3,0x0f01 00018f74: 10400052 beq r2,r0,0x000190c0 # end return -2 if timeout 00018f78: 2402fffe addiu r2,r0,0xfffe 00018f7c: 94a201a6 lhu r2,0x01a6(r5) 00018f80: 00000000 nop 00018f84: 1444fffa bne r2,r4,0x00018f70 # loop if instructions still not equal 00018f88: 24630001 addiu r3,r3,0x0001
instruction in port == instruction in RAM 00018f8c: 3c028003 lui r2,0x8003 00018f90: 8c42ad44 lw r2,-0x52bc(r2) # spu IO port left 00018f94: 00000000 nop 00018f98: 944401aa lhu r4,0x01aa(r2) # read from spu control register 00018f9c: 00000000 nop 00018fa0: 34840030 ori r4,r4,0x0030 # enable DMA read transfer mode 00018fa4: a44401aa sh r4,0x01aa(r2) # tell SPU control register 00018fa8: 08006430 j 0x000190c0 # return 0 00018fac: 00001021 addu r2,r0,r0
p1 = 3 (execute transfer)
00018fb0: 3c028003 lui r2,0x8003 00018fb4: 8c42ad94 lw r2,-0x526c(r2) # whether or not dma is reading? 00018fb8: 00000000 nop 00018fbc: 14460002 bne r2,r6,0x00018fc8 # branch if not reading 00018fc0: 34040020 ori r4,r0,0x0020 # else check if control is set to dma write mode 00018fc4: 34040030 ori r4,r0,0x0030 # if reading, check if control is set to dma read mode 00018fc8: 3c058003 lui r5,0x8003 00018fcc: 8ca5ad44 lw r5,-0x52bc(r5) # spu IO port left 00018fd0: 00001821 addu r3,r0,r0 00018fd4: 94a201aa lhu r2,0x01aa(r5) # read spu control 00018fd8: 3084ffff andi r4,r4,0xffff 00018fdc: 30420030 andi r2,r2,0x0030 # get spu sound transfer mode 00018fe0: 10440009 beq r2,r4,0x00019008 # branch if same as current state
spu state does not equal what ram says it is 00018fe4: 24630001 addiu r3,r3,0x0001 00018fe8: 2c620f01 sltiu r2,r3,0x0f01 00018fec: 10400034 beq r2,r0,0x000190c0 # end return -2 if timeout 00018ff0: 2402fffe addiu r2,r0,0xfffe 00018ff4: 94a201aa lhu r2,0x01aa(r5) 00018ff8: 00000000 nop 00018ffc: 30420030 andi r2,r2,0x0030 00019000: 1444fff9 bne r2,r4,0x00018fe8 # loop for as long as they are not equal (or timeout) 00019004: 24630001 addiu r3,r3,0x0001 # i ++
spu state equals what ram says it is 00019008: 3c038003 lui r3,0x8003 0001900c: 8c63ad94 lw r3,-0x526c(r3) # whether or not dma is reading 00019010: 34020001 ori r2,r0,0x0001
spu transfer state is set to dmaread 00019014: 14620005 bne r3,r2,0x0001902c # branch if not reading 00019018: 00000000 nop 0001901c: 0c0064de jal 0x00019378 # 00019378 - 000193a0 00019020: 26100004 addiu r16,r16,0x0004 # stack 0x20 00019024: 0800640e j 0x00019038 00019028: 3c060100 lui r6,0x0100
spu transfer state is set to dmawrite 0001902c: 0c0064d3 jal 0x0001934c # 0001934c - 00019374 00019030: 26100004 addiu r16,r16,0x0004 # stack 0x20 00019034: 3c060100 lui r6,0x0100 # 0x0100 0000 00019038: 8e04fffc lw r4,-0x0004(r16) # p2 0001903c: 3c018003 lui r1,0x8003 00019040: ac24ad98 sw r4,-0x5268(r1) # store in ram mem address to read from 00019044: 8e040000 lw r4,0x0000(r16) # size (bytes) 00019048: 3c058003 lui r5,0x8003 0001904c: 8ca5ad48 lw r5,-0x52b8(r5) # DMA SPU channel 00019050: 00041982 srl r3,r4,0x06 # p3 >> 6 00019054: 3082003f andi r2,r4,0x003f # 00019058: 0002102b sltu r2,r0,r2 # rounding 0001905c: 3c048003 lui r4,0x8003 00019060: 8c84ad98 lw r4,-0x5268(r4) # mem address 00019064: 00621821 addu r3,r3,r2 # size (blocks, rounded up) 00019068: 3c018003 lui r1,0x8003 0001906c: ac23ad9c sw r3,-0x5264(r1) 00019070: aca40000 sw r4,0x0000(r5) # set channel's mem address 00019074: 3c028003 lui r2,0x8003 00019078: 8c42ad9c lw r2,-0x5264(r2) 0001907c: 3c038003 lui r3,0x8003 00019080: 8c63ad4c lw r3,-0x52b4(r3) # DMA SPU block control 00019084: 00021400 sll r2,r2,0x10 00019088: 34420010 ori r2,r2,0x0010 0001908c: ac620000 sw r2,0x0000(r3) # number of words 00019090: 3c038003 lui r3,0x8003 00019094: 8c63ad94 lw r3,-0x526c(r3) # whether or not DMA is reading 00019098: 34020001 ori r2,r0,0x0001 0001909c: 14620003 bne r3,r2,0x000190ac # branch if not reading 000190a0: 34c60201 ori r6,r6,0x0201 # if not reading, r6 = 0x0100 0201 (RAM to device; madr per step +4; transfer mode slice; start transfer) 000190a4: 3c060100 lui r6,0x0100 000190a8: 34c60200 ori r6,r6,0x0200 # if reading, r6 = 0x0100 0200 (device to RAM, madr per step +4; transfer mode slice; start transfer) 000190ac: 3c028003 lui r2,0x8003 000190b0: 8c42ad50 lw r2,-0x52b0(r2) # DMA SPU channel control 000190b4: 00000000 nop 000190b8: ac460000 sw r6,0x0000(r2) # store command 000190bc: 00001021 addu r2,r0,r0 # return 0
end 000190c0: 8fbf0014 lw r31,0x0014(r29) 000190c4: 8fb00010 lw r16,0x0010(r29) 000190c8: 27bd0018 addiu r29,r29,0x0018 000190cc: 03e00008 jr r31 000190d0: 00000000 nop
