reactos/subsystems/mvdm/ntvdm/hardware/pit.h

81 lines
2.4 KiB
C

/*
* COPYRIGHT: GPL - See COPYING in the top level directory
* PROJECT: ReactOS Virtual DOS Machine
* FILE: subsystems/mvdm/ntvdm/hardware/pit.h
* PURPOSE: Programmable Interval Timer emulation -
* i82C54/8254 compatible
* PROGRAMMERS: Aleksandar Andrejevic <theflash AT sdf DOT lonestar DOT org>
* Hermes Belusca-Maito (hermes.belusca@sfr.fr)
*/
#ifndef _PIT_H_
#define _PIT_H_
/* DEFINES ********************************************************************/
#define PIT_CHANNELS 3
#define PIT_BASE_FREQUENCY 1193182LL
#define PIT_DATA_PORT(x) (0x40 + (x))
#define PIT_COMMAND_PORT 0x43
#define WRITE_PIT_VALUE(PitChannel, Value) \
(PitChannel).Bcd ? BCD_TO_BINARY(Value) : (Value)
#define READ_PIT_VALUE(PitChannel, Value) \
(PitChannel).Bcd ? BINARY_TO_BCD(Value) : (Value)
typedef enum _PIT_MODE
{
PIT_MODE_INT_ON_TERMINAL_COUNT,
PIT_MODE_HARDWARE_ONE_SHOT,
PIT_MODE_RATE_GENERATOR,
PIT_MODE_SQUARE_WAVE,
PIT_MODE_SOFTWARE_STROBE,
PIT_MODE_HARDWARE_STROBE
} PIT_MODE, *PPIT_MODE;
typedef VOID (WINAPI *PIT_OUT_FUNCTION)(LPVOID Param, BOOLEAN State);
typedef struct _PIT_CHANNEL
{
/* PIT Status fields */
PIT_MODE Mode;
BOOLEAN Bcd;
BYTE ReadWriteMode; // 0 --> Counter Latch ; 1 --> LSB R/W ; 2 --> MSB R/W ; 3 --> LSB then MSB R/W
/* For interleaved reading and writing in 2-byte RW mode */
BYTE ReadStatus; // Same convention as ReadWriteMode
BYTE WriteStatus; // Same convention as ReadWriteMode
/* For reading the PIT status byte */
BOOLEAN LatchStatusSet;
BYTE StatusLatch;
/* Counting */
BOOLEAN Gate;
/**/WORD CountRegister;/**/ // Our ReloadValue ???
WORD OutputLatch;
/*******************************/
WORD ReloadValue; // Max value of the counter
WORD CurrentValue; // Real value of the counter
/* PIT Output */
BOOLEAN Out; // 0: Low ; 1: High
/** HACK!! **/BOOLEAN FlipFlop;/** HACK!! **/
LPVOID OutParam;
PIT_OUT_FUNCTION OutFunction;
} PIT_CHANNEL, *PPIT_CHANNEL;
/* FUNCTIONS ******************************************************************/
VOID PitSetOutFunction(BYTE Channel, LPVOID Param, PIT_OUT_FUNCTION OutFunction);
VOID PitSetGate(BYTE Channel, BOOLEAN State);
WORD PitGetReloadValue(BYTE Channel);
VOID PitInitialize(VOID);
#endif /* _PIT_H_ */