timer.h

一个微型操作系统源码

/*
 * OSV
 * Copyright (C) 2002 Ciprian DOSOFTEI <[e-mail]>
 * All rights reserved.
 * 
 * http://backster.free.fr/osv
 *
 * This file is part of the OSV project. OSV is free software, also known as
 * "open source"; you can redistribute it and/or modify it under the terms 
 * of the GNU General Public License (GPL), version 2, as published by the Free
 * Software Foundation (FSF). To explore alternate licensing terms, contact 
 * the author at [e-mail] or [phone].
 * 
 * OSV 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 GPL for more details.  You should have
 * received a copy of the GPL along with OSV; see the file COPYING.  If
 * not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
 */

#ifndef INCTIMER
#define INCTIMER

#include <types.h>
#include <asm/io.h>

#define INTERVALSIZE 10

#include <types.h>

#define PIT_COUNTER0_REG 0x40
#define PIT_COUNTER1_REG 0x41
#define PIT_COUNTER2_REG 0x42
#define PIT_CONTROL_REG 0x43

typedef struct {
  unsigned counting_style:1;
  unsigned counter_mode:3;
  unsigned counter_access:2;
  unsigned counter_select:2;
} NOALIGN _PIT_CONTROL;

#define PIT_CSTYLE_16_BITS 0
#define PIT_CSTYLE_BCD 1

#define PIT_CM_MODE0 0
#define PIT_CM_MODE1 1
#define PIT_CM_MODE2 2
#define PIT_CM_MODE3 3
#define PIT_CM_MODE4 4
#define PIT_CM_MODE5 5

#define PIT_CA_LATCH_CMD 0
#define PIT_CA_RW_0_7 1
#define PIT_CA_RW_8_15 2
#define PIT_CA_RW_0_7_8_15 3

#define PIT_CSEL_COUNTER0 0
#define PIT_CSEL_COUNTER1 1
#define PIT_CSEL_COUNTER2 2

typedef union {
    _PIT_CONTROL fields;
    byte value;
} PIT_CONTROL;

void initTimer();
void delay_msec(const dword msec);
dword get_count();

#endif