| 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 | |
| 9 | |
| 10 | void p32x_pwm_refresh(void) |
| 11 | { |
| 12 | int cycles = Pico32x.regs[0x32 / 2]; |
| 13 | int frame_samples; |
| 14 | |
| 15 | cycles = (cycles - 1) & 0x0fff; |
| 16 | if (cycles < 500) { |
| 17 | elprintf(EL_32X|EL_PWM|EL_ANOMALY, "pwm: low cycle value: %d", cycles + 1); |
| 18 | cycles = 500; |
| 19 | } |
| 20 | pwm_cycles = cycles; |
| 21 | pwm_mult = 0x10000 / cycles; |
| 22 | if (Pico.m.pal) |
| 23 | frame_samples = OSC_PAL / 7 * 3 / 50 / cycles; |
| 24 | else |
| 25 | frame_samples = OSC_NTSC / 7 * 3 / 60 / cycles; |
| 26 | |
| 27 | pwm_line_samples = (frame_samples << 16) / scanlines_total; |
| 28 | } |
| 29 | |
| 30 | // irq for every sample?? |
| 31 | // FIXME: we need to hit more than once per line :( |
| 32 | void p32x_pwm_irq_check(int new_line) |
| 33 | { |
| 34 | int tm = (Pico32x.regs[0x30 / 2] & 0x0f00) >> 8; |
| 35 | if (tm == 0) |
| 36 | return; // TODO: verify |
| 37 | |
| 38 | if (new_line) |
| 39 | Pico32x.pwm_irq_sample_cnt += pwm_line_samples; |
| 40 | if (Pico32x.pwm_irq_sample_cnt >= (tm << 16)) { |
| 41 | Pico32x.pwm_irq_sample_cnt -= tm << 16; |
| 42 | Pico32x.sh2irqs |= P32XI_PWM; |
| 43 | p32x_update_irls(); |
| 44 | } |
| 45 | } |
| 46 | |
| 47 | unsigned int p32x_pwm_read16(unsigned int a) |
| 48 | { |
| 49 | unsigned int d = 0; |
| 50 | int predict; |
| 51 | |
| 52 | a &= 0x0e; |
| 53 | switch (a) { |
| 54 | case 0: // control |
| 55 | case 2: // cycle |
| 56 | return Pico32x.regs[(0x30 + a) / 2]; |
| 57 | |
| 58 | case 4: // L ch |
| 59 | case 6: // R ch |
| 60 | case 8: // MONO |
| 61 | predict = (pwm_line_samples * Pico.m.scanline) >> 16; |
| 62 | elprintf(EL_PWM, "pwm: read status: ptr %d/%d, predict %d", |
| 63 | pwm_frame_smp_cnt, (pwm_line_samples * scanlines_total) >> 16, predict); |
| 64 | if (pwm_frame_smp_cnt > predict + 3) |
| 65 | d |= P32XP_FULL; |
| 66 | else if (pwm_frame_smp_cnt == 0 || pwm_frame_smp_cnt < predict - 1) |
| 67 | d |= P32XP_EMPTY; |
| 68 | break; |
| 69 | } |
| 70 | |
| 71 | return d; |
| 72 | } |
| 73 | |
| 74 | void p32x_pwm_write16(unsigned int a, unsigned int d) |
| 75 | { |
| 76 | a &= 0x0e; |
| 77 | if (a == 0) // control |
| 78 | Pico32x.regs[0x30 / 2] = d; |
| 79 | else if (a == 2) { // cycle |
| 80 | Pico32x.regs[0x32 / 2] = d & 0x0fff; |
| 81 | p32x_pwm_refresh(); |
| 82 | Pico32x.pwm_irq_sample_cnt = 0; // resets? |
| 83 | } |
| 84 | else if (a <= 8) { |
| 85 | d &= 0x0fff; |
| 86 | if (d > pwm_cycles) |
| 87 | d = pwm_cycles; |
| 88 | d = (d - pwm_cycles / 2) * pwm_mult; |
| 89 | |
| 90 | if (a < 6) // L ch |
| 91 | Pico32xMem->pwm[pwm_ptr * 2] = d; |
| 92 | else if (a == 6) // R ch |
| 93 | Pico32xMem->pwm[pwm_ptr * 2 + 1] = d; |
| 94 | else // MONO |
| 95 | Pico32xMem->pwm[pwm_ptr * 2] = Pico32xMem->pwm[pwm_ptr * 2 + 1] = d; |
| 96 | |
| 97 | if (a >= 6) { // R or MONO |
| 98 | pwm_frame_smp_cnt++; |
| 99 | pwm_ptr = (pwm_ptr + 1) & (PWM_BUFF_LEN - 1); |
| 100 | elprintf(EL_PWM, "pwm: smp_cnt %d, ptr %d, smp %x", pwm_frame_smp_cnt, pwm_ptr, d); |
| 101 | } |
| 102 | } |
| 103 | } |
| 104 | |
| 105 | void p32x_pwm_update(int *buf32, int length, int stereo) |
| 106 | { |
| 107 | extern int pwm_ptr; |
| 108 | short *pwmb; |
| 109 | int step; |
| 110 | int p = 0; |
| 111 | |
| 112 | if (pwm_ptr <= 16) // at least some samples.. |
| 113 | return; |
| 114 | |
| 115 | step = (pwm_ptr << 16) / length; // FIXME: division.. |
| 116 | pwmb = Pico32xMem->pwm; |
| 117 | |
| 118 | if (stereo) |
| 119 | { |
| 120 | while (length-- > 0) { |
| 121 | *buf32++ += pwmb[0]; |
| 122 | *buf32++ += pwmb[1]; |
| 123 | |
| 124 | p += step; |
| 125 | pwmb += (p >> 16) * 2; |
| 126 | p &= 0xffff; |
| 127 | } |
| 128 | } |
| 129 | else |
| 130 | { |
| 131 | while (length-- > 0) { |
| 132 | *buf32++ += pwmb[0]; |
| 133 | |
| 134 | p += step; |
| 135 | pwmb += (p >> 16) * 2; |
| 136 | p &= 0xffff; |
| 137 | } |
| 138 | } |
| 139 | |
| 140 | elprintf(EL_PWM, "pwm_update: pwm_ptr %d, len %d, step %04x, done %d", |
| 141 | pwm_ptr, length, step, (pwmb - Pico32xMem->pwm) / 2); |
| 142 | |
| 143 | pwm_ptr = 0; |
| 144 | } |
| 145 | |