iodev/pit82c54.h

   1 /////////////////////////////////////////////////////////////////////////
   2 // $Id: pit82c54.h,v 1.16 2007/09/28 19:52:05 sshwarts Exp $
   3 /////////////////////////////////////////////////////////////////////////
   4 //
   5 /*
   6  * Emulator of an Intel 8254/82C54 Programmable Interval Timer.
   7  * Greg Alexander <yakovlev@usa.com>
   8  */
   9
  10 #ifndef _PIT_82C54_H_
  11 #define _PIT_82C54_H_ 1
  12
  13 //#include "bochs.h"
  14
  15 typedef void (*out_handler_t)(bx_bool value);
  16
  17 class pit_82C54 : public logfunctions {
  18 public:
  19   //Please do not use these.  They are public because they have to be
  20   // to compile on some platforms.  They are not to be used by other
  21   // classes.
  22
  23   enum rw_status {
  24     LSByte=0,
  25     MSByte=1,
  26     LSByte_multiple=2,
  27     MSByte_multiple=3
  28   };
  29
  30 private:
  31
  32   enum {
  33     MAX_COUNTER=2,
  34     MAX_ADDRESS=3,
  35     CONTROL_ADDRESS=3,
  36     MAX_MODE=5
  37   };
  38
  39   enum real_RW_status {
  40     LSB_real=1,
  41     MSB_real=2,
  42     BOTH_real=3
  43   };
  44
  45   enum problem_type {
  46     UNL_2P_READ=1
  47   };
  48
  49   struct counter_type {
  50     //Chip IOs;
  51     bx_bool GATE; //GATE Input value at end of cycle
  52     bx_bool OUTpin; //OUT output this cycle
  53
  54     //Architected state;
  55     Bit32u count; //Counter value this cycle
  56     Bit16u outlatch; //Output latch this cycle
  57     Bit16u inlatch; //Input latch this cycle
  58     Bit8u status_latch;
  59
  60     //Status Register data;
  61     Bit8u rw_mode; //2-bit R/W mode from command word register.
  62     Bit8u mode; //3-bit mode from command word register.
  63     bx_bool bcd_mode; //1-bit BCD vs. Binary setting.
  64     bx_bool null_count; //Null count bit of status register.
  65
  66     //Latch status data;
  67     bx_bool count_LSB_latched;
  68     bx_bool count_MSB_latched;
  69     bx_bool status_latched;
  70
  71     //Miscelaneous State;
  72     Bit32u count_binary; //Value of the count in binary.
  73     bx_bool triggerGATE; //Whether we saw GATE rise this cycle.
  74     rw_status write_state; //Read state this cycle
  75     rw_status read_state; //Read state this cycle
  76     bx_bool count_written; //Whether a count written since programmed
  77     bx_bool first_pass; //Whether or not this is the first loaded count.
  78     bx_bool state_bit_1; //Miscelaneous state bits.
  79     bx_bool state_bit_2;
  80     Bit32u next_change_time; //Next time something besides count changes.
  81                              //0 means never.
  82     out_handler_t out_handler; // OUT pin callback (for IRQ0)
  83   };
  84
  85   counter_type counter[3];
  86
  87   Bit8u controlword;
  88
  89   int seen_problems;
  90
  91   void latch_counter(counter_type & thisctr);
  92
  93   void set_OUT (counter_type & thisctr, bx_bool data);
  94
  95   void set_count (counter_type & thisctr, Bit32u data) BX_CPP_AttrRegparmN(2);
  96
  97   void set_count_to_binary (counter_type & thisctr) BX_CPP_AttrRegparmN(1);
  98
  99   void set_binary_to_count (counter_type & thisctr) BX_CPP_AttrRegparmN(1);
 100
 101   void decrement (counter_type & thisctr) BX_CPP_AttrRegparmN(1);
 102
 103   void decrement_multiple(counter_type & thisctr, Bit32u cycles) BX_CPP_AttrRegparmN(2);
 104
 105   void clock(Bit8u cnum) BX_CPP_AttrRegparmN(1);
 106
 107   void print_counter(counter_type & thisctr);
 108
 109 public:
 110   pit_82C54 (void);
 111   void init (void);
 112   void reset (unsigned type);
 113   void register_state(bx_param_c *parent);
 114
 115   void clock_all(Bit32u cycles);
 116   void clock_multiple(Bit8u cnum, Bit32u cycles);
 117
 118   Bit8u read(Bit8u address);
 119   void write(Bit8u address, Bit8u data);
 120
 121   void set_GATE(Bit8u cnum, bx_bool data);
 122   bx_bool read_GATE(Bit8u cnum);
 123
 124   bx_bool read_OUT(Bit8u cnum);
 125   void set_OUT_handler(Bit8u cnum, out_handler_t outh);
 126
 127   Bit32u get_clock_event_time(Bit8u cnum);
 128   Bit32u get_next_event_time(void);
 129   Bit16u get_inlatch(int countnum);
 130
 131   void print_cnum(Bit8u cnum);
 132 };
 133
 134 #endif