sim/m68hc11/interrupts.h

/* interrupts.h -- 68HC11 Interrupts Emulation
   Copyright 1999, 2000, 2001, 2002, 2007, 2008, 2009, 2010, 2011
   Free Software Foundation, Inc.
   Written by Stephane Carrez (stcarrez (at) worldnet.fr)

This file is part of GDB, GAS, and the GNU binutils.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef _M6811_SIM_INTERRUPTS_H
#define _M6811_SIM_INTERRUPTS_H

/* Definition of 68HC11 interrupts.  These enum are used as an index
   in the interrupt table.  */
enum M6811_INT
{
  M6811_INT_RESERVED1 = 0,
  M6811_INT_RESERVED2,
  M6811_INT_RESERVED3,
  M6811_INT_RESERVED4,
  M6811_INT_RESERVED5,
  M6811_INT_RESERVED6,
  M6811_INT_RESERVED7,
  M6811_INT_RESERVED8,

  M6811_INT_RESERVED9,
  M6811_INT_RESERVED10,
  M6811_INT_RESERVED11,

  M6811_INT_SCI,
  M6811_INT_SPI,
  M6811_INT_AINPUT,
  M6811_INT_AOVERFLOW,
  M6811_INT_TCTN,

  M6811_INT_OUTCMP5,
  M6811_INT_OUTCMP4,
  M6811_INT_OUTCMP3,
  M6811_INT_OUTCMP2,
  M6811_INT_OUTCMP1,

  M6811_INT_INCMP3,
  M6811_INT_INCMP2,
  M6811_INT_INCMP1,

  M6811_INT_RT,
  M6811_INT_IRQ,
  M6811_INT_XIRQ,
  M6811_INT_SWI,
  M6811_INT_ILLEGAL,

  M6811_INT_COPRESET,
  M6811_INT_COPFAIL,

  M6811_INT_RESET,
  M6811_INT_NUMBER
};


/* Structure to describe how to recognize an interrupt in the
   68hc11 IO regs.  */
struct interrupt_def
{
  enum M6811_INT   int_number;
  unsigned char    int_paddr;
  unsigned char    int_mask;
  unsigned char    enable_paddr;
  unsigned char    enabled_mask;
};

#define MAX_INT_HISTORY 64

/* Structure used to keep track of interrupt history.
   This is used to understand in which order interrupts were
   raised and when.  */
struct interrupt_history
{
  enum M6811_INT   type;

  /* CPU cycle when interrupt handler is called.  */
  signed64         taken_cycle;

  /* CPU cycle when the interrupt is first raised by the device.  */
  signed64         raised_cycle;
};

#define SIM_STOP_WHEN_RAISED 1
#define SIM_STOP_WHEN_TAKEN  2

/* Information and control of pending interrupts.  */
struct interrupt
{
  /* CPU cycle when the interrupt is raised by the device.  */
  signed64         cpu_cycle;

  /* Number of times the interrupt was raised.  */
  unsigned long    raised_count;

  /* Controls whether we must stop the simulator.  */
  int              stop_mode;
};


/* Management of 68HC11 interrupts:
    - We use a table of 'interrupt_def' to describe the interrupts that must be
      raised depending on IO register flags (enable and present flags).
    - We keep a mask of pending interrupts.  This mask is refreshed by
      calling 'interrupts_update_pending'.  It must be refreshed each time
      an IO register is changed.
    - 'interrupts_process' must be called after each insn. It has two purposes:
      first it maintains a min/max count of CPU cycles between which interrupts
      are masked; second it checks for pending interrupts and raise one if
      interrupts are enabled.  */
struct interrupts {
  struct _sim_cpu   *cpu;

  /* Mask of current pending interrupts.  */
  unsigned long     pending_mask;

  /* Address of vector table.  This is set depending on the
     68hc11 init mode.  */
  uint16            vectors_addr;

  /* Priority order of interrupts.  This is controlled by setting the HPRIO
     IO register.  */
  enum M6811_INT    interrupt_order[M6811_INT_NUMBER];
  struct interrupt  interrupts[M6811_INT_NUMBER];

  /* Simulator statistics to report useful debug information to users.  */

  /* - Max/Min number of CPU cycles executed with interrupts masked.  */
  signed64          start_mask_cycle;
  signed64          min_mask_cycles;
  signed64          max_mask_cycles;
  signed64          last_mask_cycles;

  /* - Same for XIRQ.  */
  signed64          xirq_start_mask_cycle;
  signed64          xirq_min_mask_cycles;
  signed64          xirq_max_mask_cycles;
  signed64          xirq_last_mask_cycles;

  /* - Total number of interrupts raised.  */
  unsigned long     nb_interrupts_raised;

  /* Interrupt history to help understand which interrupts
     were raised recently and in which order.  */
  int               history_index;
  struct interrupt_history interrupts_history[MAX_INT_HISTORY];
};

extern void interrupts_initialize     (SIM_DESC sd, struct _sim_cpu* cpu);
extern void interrupts_reset          (struct interrupts* interrupts);
extern void interrupts_update_pending (struct interrupts* interrupts);
extern int  interrupts_get_current    (struct interrupts* interrupts);
extern int  interrupts_process        (struct interrupts* interrupts);
extern void interrupts_raise          (struct interrupts* interrupts,
                                       enum M6811_INT number);

extern void interrupts_info           (SIM_DESC sd,
                                       struct interrupts* interrupts);

#endif