32x: improve 'simple' scheduling, works for 'interesting' games
[picodrive.git] / cpu / sh2mame / sh2pico.c
CommitLineData
eaa10a6e 1#include <string.h>
2
3// MAME types
4typedef signed char INT8;
5typedef signed short INT16;
6typedef signed int INT32;
7typedef unsigned int UINT32;
8typedef unsigned short UINT16;
9typedef unsigned char UINT8;
10
11// pico memhandlers
b78efee2 12unsigned int p32x_sh2_read8(unsigned int a, int id);
13unsigned int p32x_sh2_read16(unsigned int a, int id);
14unsigned int p32x_sh2_read32(unsigned int a, int id);
15void p32x_sh2_write8(unsigned int a, unsigned int d, int id);
16void p32x_sh2_write16(unsigned int a, unsigned int d, int id);
17void p32x_sh2_write32(unsigned int a, unsigned int d, int id);
18
19#define RB(a) p32x_sh2_read8(a,sh2->is_slave)
20#define RW(a) p32x_sh2_read16(a,sh2->is_slave)
21#define RL(a) p32x_sh2_read32(a,sh2->is_slave)
22#define WB(a,d) p32x_sh2_write8(a,d,sh2->is_slave)
23#define WW(a,d) p32x_sh2_write16(a,d,sh2->is_slave)
24#define WL(a,d) p32x_sh2_write32(a,d,sh2->is_slave)
eaa10a6e 25
26// some stuff from sh2comn.h
27#define T 0x00000001
28#define S 0x00000002
29#define I 0x000000f0
30#define Q 0x00000100
31#define M 0x00000200
32
33#define AM 0xc7ffffff
34
35#define FLAGS (M|Q|I|S|T)
36
37#define Rn ((opcode>>8)&15)
38#define Rm ((opcode>>4)&15)
39
40#include "sh2.c"
41
42void sh2_reset(SH2 *sh2)
43{
44 int save_is_slave;
4ea707e1 45 void *save_irqcallback;
eaa10a6e 46
4ea707e1 47 save_irqcallback = sh2->irq_callback;
eaa10a6e 48 save_is_slave = sh2->is_slave;
49
50 memset(sh2, 0, sizeof(SH2));
51
52 sh2->is_slave = save_is_slave;
4ea707e1 53 sh2->irq_callback = save_irqcallback;
eaa10a6e 54
55 sh2->pc = RL(0);
56 sh2->r[15] = RL(4);
57 sh2->sr = I;
eaa10a6e 58}
59
60/* Execute cycles - returns number of cycles actually run */
61int sh2_execute(SH2 *sh2_, int cycles)
62{
63 sh2 = sh2_;
64 sh2_icount = cycles;
2ea2cbfe 65 sh2->cycles_aim += cycles;
eaa10a6e 66
67 do
68 {
69 UINT32 opcode;
70
3cf9570b 71 if (sh2->delay)
72 {
a44737c1 73 sh2->ppc = sh2->delay;
3cf9570b 74 opcode = RW(sh2->delay);
75 sh2->pc -= 2;
76 }
77 else
a44737c1 78 {
79 sh2->ppc = sh2->pc;
3cf9570b 80 opcode = RW(sh2->pc);
a44737c1 81 }
eaa10a6e 82
83 sh2->delay = 0;
84 sh2->pc += 2;
eaa10a6e 85
86 switch (opcode & ( 15 << 12))
87 {
88 case 0<<12: op0000(opcode); break;
89 case 1<<12: op0001(opcode); break;
90 case 2<<12: op0010(opcode); break;
91 case 3<<12: op0011(opcode); break;
92 case 4<<12: op0100(opcode); break;
93 case 5<<12: op0101(opcode); break;
94 case 6<<12: op0110(opcode); break;
95 case 7<<12: op0111(opcode); break;
96 case 8<<12: op1000(opcode); break;
97 case 9<<12: op1001(opcode); break;
98 case 10<<12: op1010(opcode); break;
99 case 11<<12: op1011(opcode); break;
100 case 12<<12: op1100(opcode); break;
101 case 13<<12: op1101(opcode); break;
102 case 14<<12: op1110(opcode); break;
103 default: op1111(opcode); break;
104 }
105
106 if (sh2->test_irq && !sh2->delay)
107 {
4ea707e1 108 if (sh2->pending_irq)
109 sh2_irl_irq(sh2, sh2->pending_irq);
eaa10a6e 110 sh2->test_irq = 0;
111 }
112 sh2_icount--;
113 }
2ea2cbfe 114 while (sh2_icount > 0 || sh2->delay); /* can't interrupt before delay */
eaa10a6e 115
116 return cycles - sh2_icount;
117}
118
b78efee2 119void sh2_init(SH2 *sh2, int is_slave)
eaa10a6e 120{
121 memset(sh2, 0, sizeof(*sh2));
b78efee2 122 sh2->is_slave = is_slave;
eaa10a6e 123}
124
4ea707e1 125void sh2_irl_irq(SH2 *sh2, int level)
126{
127 int vector;
128
129 sh2->pending_irq = level;
130
131 if (level <= ((sh2->sr >> 4) & 0x0f))
132 /* masked */
133 return;
134
b78efee2 135 sh2->irq_callback(sh2->is_slave, level);
4ea707e1 136 vector = 64 + level/2;
137
138 sh2->r[15] -= 4;
139 WL(sh2->r[15], sh2->sr); /* push SR onto stack */
140 sh2->r[15] -= 4;
141 WL(sh2->r[15], sh2->pc); /* push PC onto stack */
142
143 /* set I flags in SR */
144 sh2->sr = (sh2->sr & ~I) | (level << 4);
145
146 /* fetch PC */
147 sh2->pc = RL(sh2->vbr + vector * 4);
148
149 /* 13 cycles at best */
150 sh2_icount -= 13;
151}
eaa10a6e 152