1 /* 2 * (C) Copyright 2002 3 * Daniel Engström, Omicron Ceti AB, daniel@omicron.se. 4 * 5 * See file CREDITS for list of people who contributed to this 6 * project. 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License as 10 * published by the Free Software Foundation; either version 2 of 11 * the License, or (at your option) any later version. 12 * 13 * This program is distributed in the hope that it will be useful, 14 * but WITHOUT ANY WARRANTY; without even the implied warranty of 15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 * GNU General Public License for more details. 17 * 18 * You should have received a copy of the GNU General Public License 19 * along with this program; if not, write to the Free Software 20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 21 * MA 02111-1307 USA 22 */ 23 24 25 /* i8254.h Intel 8254 PIT registers */ 26 27 28 #ifndef _ASMI386_I8254_H_ 29 #define _ASMI386_I8954_H_ 1 30 31 32 #define PIT_T0 0x00 /* PIT channel 0 count/status */ 33 #define PIT_T1 0x01 /* PIT channel 1 count/status */ 34 #define PIT_T2 0x02 /* PIT channel 2 count/status */ 35 #define PIT_COMMAND 0x03 /* PIT mode control, latch and read back */ 36 37 /* PIT Command Register Bit Definitions */ 38 39 #define PIT_CMD_CTR0 0x00 /* Select PIT counter 0 */ 40 #define PIT_CMD_CTR1 0x40 /* Select PIT counter 1 */ 41 #define PIT_CMD_CTR2 0x80 /* Select PIT counter 2 */ 42 43 #define PIT_CMD_LATCH 0x00 /* Counter Latch Command */ 44 #define PIT_CMD_LOW 0x10 /* Access counter bits 7-0 */ 45 #define PIT_CMD_HIGH 0x20 /* Access counter bits 15-8 */ 46 #define PIT_CMD_BOTH 0x30 /* Access counter bits 15-0 in two accesses */ 47 48 #define PIT_CMD_MODE0 0x00 /* Select mode 0 */ 49 #define PIT_CMD_MODE1 0x02 /* Select mode 1 */ 50 #define PIT_CMD_MODE2 0x04 /* Select mode 2 */ 51 #define PIT_CMD_MODE3 0x06 /* Select mode 3 */ 52 #define PIT_CMD_MODE4 0x08 /* Select mode 4 */ 53 #define PIT_CMD_MODE5 0x0A /* Select mode 5 */ 54 55 #endif 56