/****************************************************************************
 * INT - PRIORITY INTERRUPT subsystem
 *
 * AUTHOR: John Pultorak
 * DATE: 9/22/01
 * FILE: INT.h
 *
 * VERSIONS:
 *
 * DESCRIPTION:
 * Priority Interrupts for the Block 1 Apollo Guidance Computer prototype (AGC4).
 *
 * SOURCES:
 * Mostly based on information from "Logical Description for the Apollo
 * Guidance Computer (AGC4)", Albert Hopkins, Ramon Alonso, and Hugh
 * Blair-Smith, R-393, MIT Instrumentation Laboratory, 1963.
 *
 * NOTES:
 *
 *****************************************************************************
 */
#ifndef INT_H
#define INT_H
#include "reg.h"
enum ruptAddress
{
// Addresses for service routines of vectored interrupts
  T3RUPT_ADDR = 02004, // option 1: overflow of TIME 3
  ERRUPT_ADDR = 02010, // option 2: error signal
  DSRUPT_ADDR = 02014, // option 3: telemetry end pulse or TIME 4 overflow
  KEYRUPT_ADDR = 02020, // option 4: activity from MARK, keyboard, or tape reader
};
enum ruptNumber
{
// Option number (selects rupt priority cell)
// NOTE: the priority cells (rupt[]) are indexed 0-4, but stored in the
// RPCELL register as 1-5; (0 in RPCELL means no interrupt)
  T3RUPT = 0, // option 1: overflow of TIME 3
  ERRUPT = 1, // option 2: error signal
  DSRUPT = 2, // option 3: telemetry end pulse or TIME 4 overflow
  KEYRUPT = 3, // option 4: activity from MARK, keyboard, or tape reader
};
class regRPCELL : public reg
{
public:
  regRPCELL() :
      reg(5, "%02o")
  {
  }
};
// also inhibits additional interrupts while an interrupt is being processed
class regINHINT1 : public reg
{
public:
  regINHINT1() :
      reg(1, "%01o")
  {
  }
};
class regINHINT : public reg
{
public:
  regINHINT() :
      reg(1, "%01o")
  {
  }
};
class INT
{
public:
  friend class CLK;
  friend class MON;
  static void
  execRP_RRPA();
  static void
  execWP_GENRST();
  static void
  execWP_RPT();
  static void
  execWP_KRPT();
  static void
  execWP_CLRP();
  static void
  execWP_WOVI();
  static void
  execWP_CLINH1();
  static void
  execWP_INH();
  static void
  execWP_CLINH();
  static bool
  IRQ(); // returns true if an interrupt is requested
  static unsigned rupt[];
private:
  static void
  resetAllRupt();
  static unsigned
  getPriorityRupt();
  static regRPCELL register_RPCELL; // latches the selected priority interrupt vector (1-5)
  static regINHINT1 register_INHINT1; // inhibits interrupts for 1 instruction (on WOVI)
  static regINHINT register_INHINT; // inhibits interrupts on INHINT, reenables on RELINT
};
#endif