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more precise PIT gate emulation

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git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@499 c046a42c-6fe2-441c-8c8c-71466251a162
This commit is contained in:
bellard 2004-01-04 16:07:06 +00:00
parent dd4e27d810
commit c265508067
1 changed files with 38 additions and 5 deletions
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43
vl.c
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@ -1002,6 +1002,10 @@ static int pit_get_count(PITChannelState *s)
case 5:
counter = (s->count - d) & 0xffff;
break;
case 3:
/* XXX: may be incorrect for odd counts */
counter = s->count - ((2 * d) % s->count);
break;
default:
counter = s->count - (d % s->count);
break;
@ -1031,7 +1035,7 @@ static int pit_get_out(PITChannelState *s)
out = 0;
break;
case 3:
out = (d % s->count) < (s->count >> 1);
out = (d % s->count) < ((s->count + 1) >> 1);
break;
case 4:
case 5:
@ -1074,7 +1078,7 @@ static int pit_get_out_edges(PITChannelState *s)
ret = d2 - d1;
break;
case 3:
v = s->count - (s->count >> 1);
v = s->count - ((s->count + 1) >> 1);
d1 = (d1 + v) / s->count;
d2 = (d2 + v) / s->count;
ret = d2 - d1;
@ -1090,6 +1094,36 @@ static int pit_get_out_edges(PITChannelState *s)
return ret;
}
/* val must be 0 or 1 */
static inline void pit_set_gate(PITChannelState *s, int val)
{
switch(s->mode) {
default:
case 0:
case 4:
/* XXX: just disable/enable counting */
break;
case 1:
case 5:
if (s->gate < val) {
/* restart counting on rising edge */
s->count_load_time = cpu_get_ticks();
s->count_last_edge_check_time = s->count_load_time;
}
break;
case 2:
case 3:
if (s->gate < val) {
/* restart counting on rising edge */
s->count_load_time = cpu_get_ticks();
s->count_last_edge_check_time = s->count_load_time;
}
/* XXX: disable/enable counting */
break;
}
s->gate = val;
}
static inline void pit_load_count(PITChannelState *s, int val)
{
if (val == 0)
@ -1185,7 +1219,7 @@ uint32_t pit_ioport_read(CPUX86State *env, uint32_t addr)
void speaker_ioport_write(CPUX86State *env, uint32_t addr, uint32_t val)
{
speaker_data_on = (val >> 1) & 1;
pit_channels[2].gate = val & 1;
pit_set_gate(&pit_channels[2], val & 1);
}
uint32_t speaker_ioport_read(CPUX86State *env, uint32_t addr)
@ -1463,7 +1497,6 @@ void serial_received_byte(SerialState *s, int ch)
serial_update_irq();
break;
case 'd':
// tb_flush();
cpu_set_log(CPU_LOG_ALL);
break;
case TERM_ESCAPE:
@ -2128,7 +2161,7 @@ uint32_t kbd_read_status(CPUX86State *env, uint32_t addr)
KBDState *s = &kbd_state;
int val;
val = s->status;
#if defined(DEBUG_KBD)
#if defined(DEBUG_KBD) && 0
printf("kbd: read status=0x%02x\n", val);
#endif
return val;