eobish
diff src/dos/pit8254.h @ 7:6a350c554e46
started DOS port
author | John Tsiombikas <nuclear@member.fsf.org> |
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date | Mon, 19 Jan 2015 15:49:14 +0200 |
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1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000 1.2 +++ b/src/dos/pit8254.h Mon Jan 19 15:49:14 2015 +0200 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_ */