32x: rework scheduling/timing
[picodrive.git] / cpu / sh2 / sh2.c
... / ...
CommitLineData
1/*
2 * PicoDrive
3 * (C) notaz, 2009,2010
4 *
5 * This work is licensed under the terms of MAME license.
6 * See COPYING file in the top-level directory.
7 */
8#include <string.h>
9#include <stddef.h>
10
11#include "sh2.h"
12#include "../debug.h"
13#include "compiler.h"
14
15#define I 0xf0
16
17SH2 *sh2; // active sh2
18
19int sh2_init(SH2 *sh2, int is_slave)
20{
21 int ret = 0;
22
23 memset(sh2, 0, offsetof(SH2, mult_m68k_to_sh2));
24 sh2->is_slave = is_slave;
25 pdb_register_cpu(sh2, PDBCT_SH2, is_slave ? "ssh2" : "msh2");
26#ifdef DRC_SH2
27 ret = sh2_drc_init(sh2);
28#endif
29 return ret;
30}
31
32void sh2_finish(SH2 *sh2)
33{
34#ifdef DRC_SH2
35 sh2_drc_finish(sh2);
36#endif
37}
38
39void sh2_reset(SH2 *sh2)
40{
41 sh2->pc = p32x_sh2_read32(0, sh2);
42 sh2->r[15] = p32x_sh2_read32(4, sh2);
43 sh2->sr = I;
44 sh2->vbr = 0;
45 sh2->pending_int_irq = 0;
46}
47
48void sh2_do_irq(SH2 *sh2, int level, int vector)
49{
50 sh2->r[15] -= 4;
51 p32x_sh2_write32(sh2->r[15], sh2->sr, sh2); /* push SR onto stack */
52 sh2->r[15] -= 4;
53 p32x_sh2_write32(sh2->r[15], sh2->pc, sh2); /* push PC onto stack */
54
55 /* set I flags in SR */
56 sh2->sr = (sh2->sr & ~I) | (level << 4);
57
58 /* fetch PC */
59 sh2->pc = p32x_sh2_read32(sh2->vbr + vector * 4, sh2);
60
61 /* 13 cycles at best */
62 sh2->m68krcycles_done += C_SH2_TO_M68K(*sh2, 13);
63// sh2->icount -= 13;
64}
65
66int sh2_irl_irq(SH2 *sh2, int level, int nested_call)
67{
68 int taken;
69
70 sh2->pending_irl = level;
71 if (level < sh2->pending_int_irq)
72 level = sh2->pending_int_irq;
73 sh2->pending_level = level;
74
75 taken = (level > ((sh2->sr >> 4) & 0x0f));
76 if (taken) {
77 if (!nested_call) {
78 // not in memhandler, so handle this now (recompiler friendly)
79 // do this to avoid missing irqs that other SH2 might clear
80 int vector = sh2->irq_callback(sh2, level);
81 sh2_do_irq(sh2, level, vector);
82 }
83 else
84 sh2->test_irq = 1;
85 }
86 return taken;
87}
88
89void sh2_internal_irq(SH2 *sh2, int level, int vector)
90{
91 // FIXME: multiple internal irqs not handled..
92 // assuming internal irqs never clear until accepted
93 sh2->pending_int_irq = level;
94 sh2->pending_int_vector = vector;
95 if (level > sh2->pending_level)
96 sh2->pending_level = level;
97
98 sh2->test_irq = 1;
99}
100
101#define SH2_REG_SIZE (offsetof(SH2, macl) + sizeof(sh2->macl))
102
103void sh2_pack(const SH2 *sh2, unsigned char *buff)
104{
105 unsigned int *p;
106
107 memcpy(buff, sh2, SH2_REG_SIZE);
108 p = (void *)(buff + SH2_REG_SIZE);
109
110 p[0] = sh2->pending_int_irq;
111 p[1] = sh2->pending_int_vector;
112}
113
114void sh2_unpack(SH2 *sh2, const unsigned char *buff)
115{
116 unsigned int *p;
117
118 memcpy(sh2, buff, SH2_REG_SIZE);
119 p = (void *)(buff + SH2_REG_SIZE);
120
121 sh2->pending_int_irq = p[0];
122 sh2->pending_int_vector = p[1];
123}
124