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Some support for special latch command.

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Fix to mode 0 timers.


Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@760
This commit is contained in:
Sjoerd van der Berg 2003-03-13 21:20:22 +00:00
parent 499faf568e
commit 1e853d8dc6
1 changed files with 19 additions and 12 deletions
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31
src/hardware/timer.cpp
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@ -58,20 +58,25 @@ static void counter_latch(Bitu counter) {
Bit64s micro=PIC_MicroCount()-p->start;
switch (p->mode) {
case 0:
if (micro>p->micro) p->read_latch=p->write_latch;
else p->read_latch=(Bit16u)(p->cntr-(((float)micro/(float)p->micro)*(float)p->cntr));
break;
case 2:
case 0: /* Interrupt on Terminal Count */
/* Counter keeps on counting after passing terminal count */
micro%=p->micro;
p->read_latch=(Bit16u)(p->cntr-(((float)micro/(float)p->micro)*(float)p->cntr));
break;
case 3:
case 2: /* Rate Generator */
micro%=p->micro;
p->read_latch=(Bit16u)(p->cntr-(((float)micro/(float)p->micro)*(float)p->cntr));
break;
case 3: /* Square Wave Rate Generator */
micro%=p->micro;
micro*=2;
if (micro>p->micro) micro-=p->micro;
p->read_latch=(Bit16u)(p->cntr-(((float)micro/(float)p->micro)*(float)p->cntr));
break;
case 4: /* Software Triggered Strobe */
if (micro>p->micro) p->read_latch=p->write_latch;
else p->read_latch=(Bit16u)(p->cntr-(((float)micro/(float)p->micro)*(float)p->cntr));
break;
default:
LOG(LOG_ERROR|LOG_PIT,"Illegal Mode %d for reading counter %d",p->mode,counter);
micro%=p->micro;
@ -112,7 +117,7 @@ static void write_latch(Bit32u port,Bit8u val) {
LOG(LOG_PIT,"PIT 0 Timer at %.3g Hz mode %d",PIT_TICK_RATE/(double)p->cntr,p->mode);
break;
case 0x02: /* Timer hooked to PC-Speaker */
// LOG_DEBUG("PIT 2 Timer at %.3g Hz mode %d",PIT_TICK_RATE/(double)p->cntr,p->mode);
// LOG(LOG_PIT,"PIT 2 Timer at %.3g Hz mode %d",PIT_TICK_RATE/(double)p->cntr,p->mode);
PCSPEAKER_SetCounter(p->cntr,p->mode);
break;
default:
@ -159,14 +164,12 @@ static Bit8u read_latch(Bit32u port) {
static void write_p43(Bit32u port,Bit8u val) {
if (val & 1) {
E_Exit("PIT:BCD Counter not supported");
}
Bitu latch=(val >> 6) & 0x03;
switch (latch) {
case 0:
case 1:
case 2:
if (val & 1) E_Exit("PIT:Timer %d set to unsupported bcd mode",latch);
if ((val & 0x30) == 0) {
/* Counter latch command */
counter_latch(latch);
@ -177,9 +180,13 @@ static void write_p43(Bit32u port,Bit8u val) {
}
break;
case 3:
E_Exit("Special PIT Latch Read out thing");
if ((val & 0x20)==0) { /* Latch multiple pit counters */
if (val & 0x02) counter_latch(0);
if (val & 0x04) counter_latch(1);
if (val & 0x08) counter_latch(2);
} else E_Exit("PIT:Latch Timer Status %X",val);
break;
}
}
/* The TIMER Part */