i was wondering if anyone knows where i can find information on the R5900 processor. the CPU for the PS2. no, it''s not for an emulator, so any responses of that nature are not needed. i am writing a MIPS assembler and i have already completely the entire MIPS IV standard opcodes. i would like to add opcode extensions for the MIPS R5900 or Emotion Engine. thanx for any positive replies. To the vast majority of mankind, nothing is more agreeable than to escape the need for mental exertion... To most people, nothing is more troublesome than the effort of thinking.

This might be of interest


Emotion Engine
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This contains some basic info about psx2 cpu. Main psx2 cpu contains the R5900, a custom Sony chip design by MIPS which is practically the same as R4400 model by MIPS. Just R5900 has 6 more levels of pipeline burst cache. Also emotion engine contains FPU,vector unit vu0,vu1.R5900 cpu have 32 registers as psx1. These are R0, AT, V0, V1, A0, A1, A2, A3, T0, T1, T2, T3, T4, T5, T6, T7, S0, S1, S2, S3, S4, S5, S6, S7, T8, T9, K0, K1, GP, SP, FP, RA.
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Detailed info about cpu registers
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0 zero always 0
1 at Assembler temporary.
2 v0 Subroutine return values
3 v1 Subroutine return values
4 a0 Subroutine arguments
5 a1 Subroutine arguments
6 a2 Subroutine arguments
7 a3 Subroutine arguments
8 t0 Temporaries, may be changed by subroutines
9 t1 Temporaries, may be changed by subroutines
10 t2 Temporaries, may be changed by subroutines
11 t3 Temporaries, may be changed by subroutines
12 t4 Temporaries, may be changed by subroutines
13 t5 Temporaries, may be changed by subroutines
14 t6 Temporaries, may be changed by subroutines
15 t7 Temporaries, may be changed by subroutines
16 s0 Register variables, must be saved by subs.
17 s1 Register variables, must be saved by subs.
18 s2 Register variables, must be saved by subs.
19 s3 Register variables, must be saved by subs.
20 s4 Register variables, must be saved by subs.
21 s5 Register variables, must be saved by subs.
22 s6 Register variables, must be saved by subs.
23 s7 Register variables, must be saved by subs.
24 t8 Temporaries, may be changed by subroutines
25 t9 Temporaries, may be changed by subroutines
26 k0 Reserved for the kernel
27 k1 Reserved for the kernel
28 gp Global pointer
29 sp Stack pointer
30 fp subs can use this as a frame pointer
31 ra Return address


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