rayzor

diff src/pit8254.h @ 0:2a5340a6eee4

rayzor first commit
author John Tsiombikas <nuclear@member.fsf.org>
date Sat, 05 Apr 2014 08:46:27 +0300
parents
children a826bf0fb169
line diff
     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/src/pit8254.h	Sat Apr 05 08:46:27 2014 +0300
     1.3 @@ -0,0 +1,34 @@
     1.4 +#ifndef PIT8254_H_
     1.5 +#define PIT8254_H_
     1.6 +
     1.7 +/* frequency of the oscillator driving the 8254 timer */
     1.8 +#define OSC_FREQ_HZ		1193182
     1.9 +
    1.10 +/* I/O ports connected to the 8254 */
    1.11 +#define PORT_DATA0	0x40
    1.12 +#define PORT_DATA1	0x41
    1.13 +#define PORT_DATA2	0x42
    1.14 +#define PORT_CMD	0x43
    1.15 +
    1.16 +/* command bits */
    1.17 +#define CMD_CHAN0			0
    1.18 +#define CMD_CHAN1			(1 << 6)
    1.19 +#define CMD_CHAN2			(2 << 6)
    1.20 +#define CMD_RDBACK			(3 << 6)
    1.21 +
    1.22 +#define CMD_LATCH			0
    1.23 +#define CMD_ACCESS_LOW		(1 << 4)
    1.24 +#define CMD_ACCESS_HIGH		(2 << 4)
    1.25 +#define CMD_ACCESS_BOTH		(3 << 4)
    1.26 +
    1.27 +#define CMD_OP_INT_TERM		0
    1.28 +#define CMD_OP_ONESHOT		(1 << 1)
    1.29 +#define CMD_OP_RATE			(2 << 1)
    1.30 +#define CMD_OP_SQWAVE		(3 << 1)
    1.31 +#define CMD_OP_SW_STROBE	(4 << 1)
    1.32 +#define CMD_OP_HW_STROBE	(5 << 1)
    1.33 +
    1.34 +#define CMD_MODE_BIN		0
    1.35 +#define CMD_MODE_BCD		1
    1.36 +
    1.37 +#endif	/* PIT8254_H_ */