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1 | #include "../pico_int.h" |
2 | |
3 | static int pwm_line_samples; |
4 | static int pwm_cycles; |
5 | static int pwm_mult; |
6 | static int pwm_ptr; |
7 | int pwm_frame_smp_cnt; |
8 | |
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9 | static int timer_line_ticks[2]; |
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10 | |
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11 | // timers. This includes PWM timer in 32x and internal SH2 timers |
12 | void p32x_timers_recalc(void) |
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13 | { |
14 | int cycles = Pico32x.regs[0x32 / 2]; |
15 | int frame_samples; |
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16 | int tmp, i; |
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17 | |
18 | cycles = (cycles - 1) & 0x0fff; |
19 | if (cycles < 500) { |
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20 | elprintf(EL_32X|EL_PWM|EL_ANOMALY, "pwm: low cycle value: %d", cycles + 1); |
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21 | cycles = 500; |
22 | } |
23 | pwm_cycles = cycles; |
24 | pwm_mult = 0x10000 / cycles; |
25 | if (Pico.m.pal) |
26 | frame_samples = OSC_PAL / 7 * 3 / 50 / cycles; |
27 | else |
28 | frame_samples = OSC_NTSC / 7 * 3 / 60 / cycles; |
29 | |
30 | pwm_line_samples = (frame_samples << 16) / scanlines_total; |
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31 | |
32 | // SH2 timer step |
33 | for (i = 0; i < 2; i++) { |
34 | tmp = PREG8(Pico32xMem->sh2_peri_regs[i], 0x80) & 7; |
35 | // Sclk cycles per timer tick |
36 | if (tmp) |
37 | cycles = 0x20 << tmp; |
38 | else |
39 | cycles = 2; |
40 | if (Pico.m.pal) |
41 | tmp = OSC_PAL / 7 * 3 / 50 / scanlines_total; |
42 | else |
43 | tmp = OSC_NTSC / 7 * 3 / 60 / scanlines_total; |
44 | timer_line_ticks[i] = (tmp << 16) / cycles; |
45 | elprintf(EL_32X, "timer_line_ticks[%d] = %.3f", i, (double)timer_line_ticks[i] / 0x10000); |
46 | } |
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47 | } |
48 | |
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49 | // PWM irq for every tm samples |
50 | void p32x_timers_do(int new_line) |
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51 | { |
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52 | int tm, cnt, i; |
53 | tm = (Pico32x.regs[0x30 / 2] & 0x0f00) >> 8; |
54 | if (tm != 0) { |
55 | if (new_line) |
56 | Pico32x.pwm_irq_sample_cnt += pwm_line_samples; |
57 | if (Pico32x.pwm_irq_sample_cnt >= (tm << 16)) { |
58 | Pico32x.pwm_irq_sample_cnt -= tm << 16; |
59 | Pico32x.sh2irqs |= P32XI_PWM; |
60 | p32x_update_irls(); |
61 | } |
62 | } |
63 | |
64 | if (!new_line) |
65 | return; |
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66 | |
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67 | for (i = 0; i < 2; i++) { |
68 | void *pregs = Pico32xMem->sh2_peri_regs[i]; |
69 | if (PREG8(pregs, 0x80) & 0x20) { // TME |
70 | cnt = PREG8(pregs, 0x81); |
71 | cnt += timer_line_ticks[i]; |
72 | if (cnt >= 0x100) { |
73 | int level = PREG8(pregs, 0xe3) >> 4; |
74 | int vector = PREG8(pregs, 0xe4) & 0x7f; |
75 | elprintf(EL_32X, "%csh2 WDT irq (%d, %d)", i ? 's' : 'm', level, vector); |
76 | sh2_internal_irq(&sh2s[i], level, vector); |
77 | } |
78 | cnt &= 0xff; |
79 | PREG8(pregs, 0x81) = cnt; |
80 | } |
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81 | } |
82 | } |
83 | |
84 | unsigned int p32x_pwm_read16(unsigned int a) |
85 | { |
86 | unsigned int d = 0; |
87 | int predict; |
88 | |
89 | a &= 0x0e; |
90 | switch (a) { |
91 | case 0: // control |
92 | case 2: // cycle |
93 | return Pico32x.regs[(0x30 + a) / 2]; |
94 | |
95 | case 4: // L ch |
96 | case 6: // R ch |
97 | case 8: // MONO |
98 | predict = (pwm_line_samples * Pico.m.scanline) >> 16; |
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99 | elprintf(EL_PWM, "pwm: read status: ptr %d/%d, predict %d", |
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100 | pwm_frame_smp_cnt, (pwm_line_samples * scanlines_total) >> 16, predict); |
101 | if (pwm_frame_smp_cnt > predict + 3) |
102 | d |= P32XP_FULL; |
103 | else if (pwm_frame_smp_cnt == 0 || pwm_frame_smp_cnt < predict - 1) |
104 | d |= P32XP_EMPTY; |
105 | break; |
106 | } |
107 | |
108 | return d; |
109 | } |
110 | |
111 | void p32x_pwm_write16(unsigned int a, unsigned int d) |
112 | { |
113 | a &= 0x0e; |
114 | if (a == 0) // control |
115 | Pico32x.regs[0x30 / 2] = d; |
116 | else if (a == 2) { // cycle |
117 | Pico32x.regs[0x32 / 2] = d & 0x0fff; |
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118 | p32x_timers_recalc(); |
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119 | Pico32x.pwm_irq_sample_cnt = 0; // resets? |
120 | } |
121 | else if (a <= 8) { |
122 | d &= 0x0fff; |
123 | if (d > pwm_cycles) |
124 | d = pwm_cycles; |
125 | d = (d - pwm_cycles / 2) * pwm_mult; |
126 | |
127 | if (a < 6) // L ch |
128 | Pico32xMem->pwm[pwm_ptr * 2] = d; |
129 | else if (a == 6) // R ch |
130 | Pico32xMem->pwm[pwm_ptr * 2 + 1] = d; |
131 | else // MONO |
132 | Pico32xMem->pwm[pwm_ptr * 2] = Pico32xMem->pwm[pwm_ptr * 2 + 1] = d; |
133 | |
134 | if (a >= 6) { // R or MONO |
135 | pwm_frame_smp_cnt++; |
136 | pwm_ptr = (pwm_ptr + 1) & (PWM_BUFF_LEN - 1); |
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137 | elprintf(EL_PWM, "pwm: smp_cnt %d, ptr %d, smp %x", pwm_frame_smp_cnt, pwm_ptr, d); |
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138 | } |
139 | } |
140 | } |
141 | |
142 | void p32x_pwm_update(int *buf32, int length, int stereo) |
143 | { |
144 | extern int pwm_ptr; |
145 | short *pwmb; |
146 | int step; |
147 | int p = 0; |
148 | |
149 | if (pwm_ptr <= 16) // at least some samples.. |
150 | return; |
151 | |
152 | step = (pwm_ptr << 16) / length; // FIXME: division.. |
153 | pwmb = Pico32xMem->pwm; |
154 | |
155 | if (stereo) |
156 | { |
157 | while (length-- > 0) { |
158 | *buf32++ += pwmb[0]; |
159 | *buf32++ += pwmb[1]; |
160 | |
161 | p += step; |
162 | pwmb += (p >> 16) * 2; |
163 | p &= 0xffff; |
164 | } |
165 | } |
166 | else |
167 | { |
168 | while (length-- > 0) { |
169 | *buf32++ += pwmb[0]; |
170 | |
171 | p += step; |
172 | pwmb += (p >> 16) * 2; |
173 | p &= 0xffff; |
174 | } |
175 | } |
176 | |
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177 | elprintf(EL_PWM, "pwm_update: pwm_ptr %d, len %d, step %04x, done %d", |
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178 | pwm_ptr, length, step, (pwmb - Pico32xMem->pwm) / 2); |
179 | |
180 | pwm_ptr = 0; |
181 | } |
182 | |