+/*
+ * PicoDrive
+ * (C) notaz, 2009,2010
+ *
+ * This work is licensed under the terms of MAME license.
+ * See COPYING file in the top-level directory.
+ */
#include "../pico_int.h"
-static int pwm_line_samples;
+static int pwm_cycle_counter;
static int pwm_cycles;
static int pwm_mult;
static int pwm_ptr;
-int pwm_frame_smp_cnt;
+static int pwm_smp_cnt;
+static int pwm_smp_expect;
-void p32x_pwm_refresh(void)
+static int timer_cycles[2];
+static int timer_tick_cycles[2];
+
+// timers. This includes PWM timer in 32x and internal SH2 timers
+void p32x_timers_recalc(void)
{
int cycles = Pico32x.regs[0x32 / 2];
- int frame_samples;
+ int tmp, i;
cycles = (cycles - 1) & 0x0fff;
if (cycles < 500) {
}
pwm_cycles = cycles;
pwm_mult = 0x10000 / cycles;
- if (Pico.m.pal)
- frame_samples = OSC_PAL / 7 * 3 / 50 / cycles;
- else
- frame_samples = OSC_NTSC / 7 * 3 / 60 / cycles;
- pwm_line_samples = (frame_samples << 16) / scanlines_total;
+ // SH2 timer step
+ for (i = 0; i < 2; i++) {
+ tmp = PREG8(Pico32xMem->sh2_peri_regs[i], 0x80) & 7;
+ // Sclk cycles per timer tick
+ if (tmp)
+ cycles = 0x20 << tmp;
+ else
+ cycles = 2;
+ timer_tick_cycles[i] = cycles;
+ elprintf(EL_32X, "WDT cycles[%d] = %d", i, cycles);
+ }
}
-// irq for every sample??
-// FIXME: we need to hit more than once per line :(
-void p32x_pwm_irq_check(int new_line)
+// PWM irq for every tm samples
+void p32x_timers_do(unsigned int cycles)
{
- int tm = (Pico32x.regs[0x30 / 2] & 0x0f00) >> 8;
- if (tm == 0)
- return; // TODO: verify
-
- if (new_line)
- Pico32x.pwm_irq_sample_cnt += pwm_line_samples;
- if (Pico32x.pwm_irq_sample_cnt >= (tm << 16)) {
- Pico32x.pwm_irq_sample_cnt -= tm << 16;
- Pico32x.sh2irqs |= P32XI_PWM;
- p32x_update_irls();
+ int cnt, i;
+
+ cycles *= 3;
+
+ // since we run things in async fashion, allow pwm to lag behind
+ // but don't allow our "queue" to be infinite
+ cnt = pwm_smp_expect - pwm_smp_cnt;
+ if (cnt <= 0 || cnt * pwm_cycles < OSC_NTSC/7*3 / 60 / 2) {
+ pwm_cycle_counter += cycles;
+ while (pwm_cycle_counter > pwm_cycles) {
+ pwm_cycle_counter -= pwm_cycles;
+ pwm_smp_expect++;
+ }
}
+
+ // WDT timers
+ for (i = 0; i < 2; i++) {
+ void *pregs = Pico32xMem->sh2_peri_regs[i];
+ if (PREG8(pregs, 0x80) & 0x20) { // TME
+ timer_cycles[i] += cycles;
+ cnt = PREG8(pregs, 0x81);
+ while (timer_cycles[i] >= timer_tick_cycles[i]) {
+ timer_cycles[i] -= timer_tick_cycles[i];
+ cnt++;
+ }
+ if (cnt >= 0x100) {
+ int level = PREG8(pregs, 0xe3) >> 4;
+ int vector = PREG8(pregs, 0xe4) & 0x7f;
+ elprintf(EL_32X, "%csh2 WDT irq (%d, %d)",
+ i ? 's' : 'm', level, vector);
+ sh2_internal_irq(&sh2s[i], level, vector);
+ cnt &= 0xff;
+ }
+ PREG8(pregs, 0x81) = cnt;
+ }
+ }
+}
+
+static int p32x_pwm_schedule_(void)
+{
+ int tm;
+
+ if (Pico32x.emu_flags & P32XF_PWM_PEND)
+ return 0; // already scheduled
+ if (Pico32x.sh2irqs & P32XI_PWM)
+ return 0; // previous not acked
+ if (!((Pico32x.sh2irq_mask[0] | Pico32x.sh2irq_mask[1]) & 1))
+ return 0; // masked by everyone
+
+ Pico32x.emu_flags |= P32XF_PWM_PEND;
+ tm = (Pico32x.regs[0x30 / 2] & 0x0f00) >> 8;
+ tm = ((tm - 1) & 0x0f) + 1;
+ return pwm_cycles * tm / 3;
+}
+
+void p32x_pwm_schedule(unsigned int now)
+{
+ int after = p32x_pwm_schedule_();
+ if (after != 0)
+ p32x_event_schedule(now, P32X_EVENT_PWM, after);
+}
+
+void p32x_pwm_schedule_sh2(SH2 *sh2)
+{
+ int after = p32x_pwm_schedule_();
+ if (after != 0)
+ p32x_event_schedule_sh2(sh2, P32X_EVENT_PWM, after);
}
unsigned int p32x_pwm_read16(unsigned int a)
{
unsigned int d = 0;
- int predict;
+ int diff;
a &= 0x0e;
switch (a) {
case 4: // L ch
case 6: // R ch
case 8: // MONO
- predict = (pwm_line_samples * Pico.m.scanline) >> 16;
- elprintf(EL_PWM, "pwm: read status: ptr %d/%d, predict %d",
- pwm_frame_smp_cnt, (pwm_line_samples * scanlines_total) >> 16, predict);
- if (pwm_frame_smp_cnt > predict + 3)
+ diff = pwm_smp_cnt - pwm_smp_expect;
+ elprintf(EL_PWM, "pwm: read status: ptr %d/%d %d",
+ pwm_smp_cnt, pwm_smp_expect, diff);
+ if (diff > 3)
d |= P32XP_FULL;
- else if (pwm_frame_smp_cnt == 0 || pwm_frame_smp_cnt < predict - 1)
+ else if (diff < 0)
d |= P32XP_EMPTY;
break;
}
Pico32x.regs[0x30 / 2] = d;
else if (a == 2) { // cycle
Pico32x.regs[0x32 / 2] = d & 0x0fff;
- p32x_pwm_refresh();
+ p32x_timers_recalc();
Pico32x.pwm_irq_sample_cnt = 0; // resets?
}
else if (a <= 8) {
Pico32xMem->pwm[pwm_ptr * 2] = Pico32xMem->pwm[pwm_ptr * 2 + 1] = d;
if (a >= 6) { // R or MONO
- pwm_frame_smp_cnt++;
+ pwm_smp_cnt++;
pwm_ptr = (pwm_ptr + 1) & (PWM_BUFF_LEN - 1);
- elprintf(EL_PWM, "pwm: smp_cnt %d, ptr %d, smp %x", pwm_frame_smp_cnt, pwm_ptr, d);
+ elprintf(EL_PWM, "pwm: smp_cnt %d, ptr %d, smp %x",
+ pwm_smp_cnt, pwm_ptr, d);
}
}
}
void p32x_pwm_update(int *buf32, int length, int stereo)
{
- extern int pwm_ptr;
short *pwmb;
int step;
int p = 0;
pwm_ptr = 0;
}
+// vim:shiftwidth=2:ts=2:expandtab
notaz.gp2x.de / picodrive.git / blobdiff