3 * Daniel Engström, Omicron Ceti AB, daniel@omicron.se.
5 * See file CREDITS for list of people who contributed to this
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.
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.
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,
25 /* i8254.h Intel 8254 PIT registers */
28 #ifndef _ASMI386_I8254_H_
29 #define _ASMI386_I8954_H_ 1
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 */
37 /* PIT Command Register Bit Definitions */
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 */
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 */
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 */