/* * Copyright (C) 2002-2003 The DOSBox Team * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Library General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* $Id: timer.cpp,v 1.16 2003-09-01 20:16:59 qbix79 Exp $ */ #include "dosbox.h" #include "inout.h" #include "pic.h" #include "bios.h" #include "mem.h" #include "dosbox.h" #include "mixer.h" #include "timer.h" struct PIT_Block { Bit8u mode; /* Current Counter Mode */ Bitu cntr; Bits micro; Bit64u start; Bit8u latch_mode; Bit8u read_state; Bit16s read_latch; Bit8u write_state; Bit16u write_latch; }; static PIT_Block pit[3]; static void PIT0_Event(void) { PIC_ActivateIRQ(0); if (pit[0].mode!=0) PIC_AddEvent(PIT0_Event,pit[0].micro); } static void counter_latch(Bitu counter) { /* Fill the read_latch of the selected counter with current count */ PIT_Block * p=&pit[counter]; Bit64s micro=PIC_MicroCount()-p->start; switch (p->mode) { case 0: /* Interrupt on Terminal Count */ /* Counter keeps on counting after passing terminal count */ if (micro>p->micro) { micro-=p->micro; micro%=(Bit64u)(1000000/((float)PIT_TICK_RATE/(float)0x10000)); p->read_latch=(Bit16u)(0x10000-(((double)micro/(double)p->micro)*(double)0x10000)); } else { p->read_latch=(Bit16u)(p->cntr-(((double)micro/(double)p->micro)*(double)p->cntr)); } break; case 2: /* Rate Generator */ micro%=p->micro; p->read_latch=(Bit16u)(p->cntr-(((double)micro/(double)p->micro)*(double)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-(((double)micro/(double)p->micro)*(double)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-(((double)micro/(double)p->micro)*(double)p->cntr)); break; default: LOG(LOG_PIT,LOG_ERROR)("Illegal Mode %d for reading counter %d",p->mode,counter); micro%=p->micro; p->read_latch=(Bit16u)(p->cntr-(((double)micro/(double)p->micro)*(double)p->cntr)); break; } } static void write_latch(Bit32u port,Bit8u val) { Bitu counter=port-0x40; PIT_Block * p=&pit[counter]; switch (p->write_state) { case 0: p->write_latch = p->write_latch | ((val & 0xff) << 8); p->write_state = 3; break; case 3: p->write_latch = val & 0xff; p->write_state = 0; break; case 1: p->write_latch = val & 0xff; break; case 2: p->write_latch = (val & 0xff) << 8; break; } if (p->write_state != 0) { if (p->write_latch == 0) p->cntr = 0x10000; else p->cntr = p->write_latch; p->start=PIC_MicroCount(); p->micro=(Bits)(1000000/((float)PIT_TICK_RATE/(float)p->cntr)); switch (counter) { case 0x00: /* Timer hooked to IRQ 0 */ PIC_RemoveEvents(PIT0_Event); PIC_AddEvent(PIT0_Event,p->micro); LOG(LOG_PIT,LOG_NORMAL)("PIT 0 Timer at %.3g Hz mode %d",PIT_TICK_RATE/(double)p->cntr,(Bit32u)p->mode); break; case 0x02: /* Timer hooked to PC-Speaker */ // 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: LOG(LOG_PIT,LOG_ERROR)("PIT:Illegal timer selected for writing"); } } } static Bit8u read_latch(Bit32u port) { Bit32u counter=port-0x40; if (pit[counter].read_latch == -1) counter_latch(counter); Bit8u ret; switch (pit[counter].read_state) { case 0: /* read MSB & return to state 3 */ ret=(pit[counter].read_latch >> 8) & 0xff; pit[counter].read_state = 3; pit[counter].read_latch = -1; break; case 3: /* read LSB followed by MSB */ ret = (pit[counter].read_latch & 0xff); if (pit[counter].mode & 0x80) pit[counter].mode &= 7; /* moved here */ else pit[counter].read_state = 0; break; case 1: /* read LSB */ ret = (pit[counter].read_latch & 0xff); pit[counter].read_latch = -1; break; case 2: /* read MSB */ ret = (pit[counter].read_latch >> 8) & 0xff; pit[counter].read_latch = -1; break; default: ret=0; E_Exit("Timer.cpp: error in readlatch"); break; } return ret; } static void write_p43(Bit32u port,Bit8u val) { 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); } else { pit[latch].read_state = (val >> 4) & 0x03; pit[latch].write_state = (val >> 4) & 0x03; pit[latch].mode = (val >> 1) & 0x07; } break; case 3: 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 if ((val & 0x10)==0) { /* Latch status words */ LOG(LOG_PIT,LOG_ERROR)("Unsupported Latch status word call"); } else LOG(LOG_PIT,LOG_ERROR)("Unhandled command:%X",val); break; } } void TIMER_Init(Section* sect) { IO_RegisterWriteHandler(0x40,write_latch,"PIT Timer 0"); IO_RegisterWriteHandler(0x42,write_latch,"PIT Timer 2"); IO_RegisterWriteHandler(0x43,write_p43,"PIT Mode Control"); IO_RegisterReadHandler(0x40,read_latch,"PIT Timer 0"); // IO_RegisterReadHandler(0x41,read_p41,"PIT Timer 1"); IO_RegisterReadHandler(0x42,read_latch,"PIT Timer 2"); /* Setup Timer 0 */ pit[0].cntr=0x10000; pit[0].write_state = 3; pit[0].read_state = 3; pit[0].read_latch=-1; pit[0].write_latch=0; pit[0].mode=3; pit[0].micro=(Bits)(1000000/((float)PIT_TICK_RATE/(float)pit[0].cntr)); pit[2].micro=100; pit[2].read_latch=-1; /* MadTv1 */ PIC_AddEvent(PIT0_Event,pit[0].micro); }