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/////////////////////////////////////////////////////////////////////////
// $Id: pit82c54.h,v 1.12 2003/03/02 23:59:11 cbothamy Exp $
/////////////////////////////////////////////////////////////////////////
//
/*
* Emulator of an Intel 8254/82C54 Programmable Interval Timer.
* Greg Alexander <yakovlev@usa.com>
*
* This code is not yet linked into Bochs, but has been included so
* that you can experiment with it. (bbd)
*/
#ifndef _PIT_82C54_H_
#define _PIT_82C54_H_ 1
#include "bochs.h"
class pit_82C54 : public logfunctions {
public:
//Please do not use these. They are public because they have to be
// to compile on some platforms. They are not to be used by other
// classes.
enum rw_status {
LSByte=0,
MSByte=1,
LSByte_multiple=2,
MSByte_multiple=3
};
private:
enum {
MAX_COUNTER=2,
MAX_ADDRESS=3,
CONTROL_ADDRESS=3,
MAX_MODE=5
};
enum real_RW_status {
LSB_real=1,
MSB_real=2,
BOTH_real=3
};
enum problem_type {
UNL_2P_READ=1
};
struct counter_type {
//Chip IOs;
bool GATE; //GATE Input value at end of cycle
bool OUTpin; //OUT output this cycle
//Architected state;
Bit32u count; //Counter value this cycle
Bit16u outlatch; //Output latch this cycle
Bit16u inlatch; //Input latch this cycle
Bit8u status_latch;
//Status Register data;
Bit8u rw_mode; //2-bit R/W mode from command word register.
Bit8u mode; //3-bit mode from command word register.
bool bcd_mode; //1-bit BCD vs. Binary setting.
bool null_count; //Null count bit of status register.
//Latch status data;
bool count_LSB_latched;
bool count_MSB_latched;
bool status_latched;
//Miscelaneous State;
Bit32u count_binary; //Value of the count in binary.
bool triggerGATE; //Whether we saw GATE rise this cycle.
rw_status write_state; //Read state this cycle
rw_status read_state; //Read state this cycle
bool count_written; //Whether a count written since programmed
bool first_pass; //Whether or not this is the first loaded count.
bool state_bit_1; //Miscelaneous state bits.
bool state_bit_2;
Bit32u next_change_time; //Next time something besides count changes.
//0 means never.
};
counter_type counter[3];
Bit8u controlword;
int seen_problems;
void latch_counter(counter_type & thisctr);
void set_OUT (counter_type & thisctr, bool data);
void set_count (counter_type & thisctr, Bit32u data) BX_CPP_AttrRegparmN(2);
void set_count_to_binary (counter_type & thisctr) BX_CPP_AttrRegparmN(1);
void set_binary_to_count (counter_type & thisctr) BX_CPP_AttrRegparmN(1);
void decrement (counter_type & thisctr) BX_CPP_AttrRegparmN(1);
void decrement_multiple(counter_type & thisctr, Bit32u cycles) BX_CPP_AttrRegparmN(2);
void clock(Bit8u cnum) BX_CPP_AttrRegparmN(1);
void print_counter(counter_type & thisctr);
public:
void init (void);
void reset (unsigned type);
pit_82C54 (void);
void clock_all(Bit32u cycles);
void clock_multiple(Bit8u cnum, Bit32u cycles);
Bit8u read(Bit8u address);
void write(Bit8u address, Bit8u data);
void set_GATE(Bit8u cnum, bool data);
bool read_GATE(Bit8u cnum);
bool read_OUT(Bit8u cnum);
Bit32u get_clock_event_time(Bit8u cnum);
Bit32u get_next_event_time(void);
void print_cnum(Bit8u cnum);
};
#endif
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