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#ifndef __ALT_EXCEPTIONS_H__

#define __ALT_EXCEPTIONS_H__

/******************************************************************************

*                                                                             *

* License Agreement                                                           *

*                                                                             *

* Copyright (c) 2008 Altera Corporation, San Jose, California, USA.           *

* All rights reserved.                                                        *

*                                                                             *

* Permission is hereby granted, free of charge, to any person obtaining a     *

* copy of this software and associated documentation files (the "Software"),  *

* to deal in the Software without restriction, including without limitation   *

* the rights to use, copy, modify, merge, publish, distribute, sublicense,    *

* and/or sell copies of the Software, and to permit persons to whom the       *

* Software is furnished to do so, subject to the following conditions:        *

*                                                                             *

* The above copyright notice and this permission notice shall be included in  *

* all copies or substantial portions of the Software.                         *

*                                                                             *

* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR  *

* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,    *

* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE *

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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING     *

* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER         *

* DEALINGS IN THE SOFTWARE.                                                   *

*                                                                             *

* This agreement shall be governed in all respects by the laws of the State   *

* of California and by the laws of the United States of America.              *

*                                                                             *

******************************************************************************/

#include "alt_types.h"

#include "system.h"

#ifdef __cplusplus

extern "C"

{

#endif /* __cplusplus */

/*

 * This file defines instruction-generated exception handling and registry

 * API, exception type enumeration, and handler return value enumeration for

 * Nios II.

 */

/*

 * The following enumeration describes the value in the CPU EXCEPTION

 * register CAUSE bit field. Not all exception types will cause the

 * processor to go to the exception vector; these are provided for

 * reference.

 */

enum alt_exception_cause_e {

  /* Exeption causes that will cause jump to exception vector */

  NIOS2_EXCEPTION_INTERRUPT                  = 2,

  NIOS2_EXCEPTION_TRAP_INST                  = 3,

  NIOS2_EXCEPTION_UNIMPLEMENTED_INST         = 4,

  NIOS2_EXCEPTION_ILLEGAL_INST               = 5,

  NIOS2_EXCEPTION_MISALIGNED_DATA_ADDR       = 6,

  NIOS2_EXCEPTION_MISALIGNED_TARGET_PC       = 7,

  NIOS2_EXCEPTION_DIVISION_ERROR             = 8,

  NIOS2_EXCEPTION_SUPERVISOR_ONLY_INST_ADDR  = 9,

  NIOS2_EXCEPTION_SUPERVISOR_ONLY_INST       = 10,

  NIOS2_EXCEPTION_SUPERVISOR_ONLY_DATA_ADDR  = 11,

  NIOS2_EXCEPTION_TLB_MISS                   = 12,

  NIOS2_EXCEPTION_TLB_EXECUTE_PERM_VIOLATION = 13,

  NIOS2_EXCEPTION_MPU_INST_REGION_VIOLATION  = 16,

  /* Exception causes that will NOT cause a jump to exception vector */

  NIOS2_EXCEPTION_RESET                      = 0,

  NIOS2_EXCEPTION_CPU_ONLY_RESET_REQUEST     = 1,

  NIOS2_EXCEPTION_TLB_READ_PERM_VIOLATION    = 14,

  NIOS2_EXCEPTION_TLB_WRITE_PERM_VIOLATION   = 15,

  NIOS2_EXCEPTION_MPU_DATA_REGION_VIOLATION  = 17,

  /*

   * This value is passed to an exception handler's cause argument if

   * "extra exceptions" information (EXECPTION) register is not

   * present in the processor hardware configuration.

   */

  NIOS2_EXCEPTION_CAUSE_NOT_PRESENT          = -1

};

typedef enum alt_exception_cause_e alt_exception_cause;

/*

 * These define valid return values for a user-defined instruction-generated

 * exception handler. The handler should return one of these to indicate

 * whether to re-issue the instruction that triggered the exception, or to

 * skip it.

 */

enum alt_exception_result_e {

  NIOS2_EXCEPTION_RETURN_REISSUE_INST = 0,

  NIOS2_EXCEPTION_RETURN_SKIP_INST    = 1

};

typedef enum alt_exception_result_e alt_exception_result;

/*

 * alt_instruction_exception_register() can be used to register an exception

 * handler for instruction-generated exceptions that are not handled by the

 * built-in exception handler (i.e. for interrupts).

 *

 * The registry API is optionally enabled through the "Enable

 * Instruction-related Exception API" HAL BSP setting, which will

 * define the macro below.

 */

#ifdef ALT_INCLUDE_INSTRUCTION_RELATED_EXCEPTION_API

void alt_instruction_exception_register (

  alt_exception_result (*exception_handler)(

    alt_exception_cause cause,

    alt_u32 exception_pc,

    alt_u32 bad_addr) );

#endif /*ALT_INCLUDE_INSTRUCTION_RELATED_EXCEPTION_API */

/*

 * alt_exception_cause_generated_bad_addr() indicates whether a particular

 * exception cause value was from an exception-type that generated a valid

 * address in the BADADDR register. The contents of BADADDR is passed to

 * a user-registered exception handler in all cases, whether valid or not.

 * This routine should be called to validate the bad_addr argument to

 * your exception handler.

 */

int alt_exception_cause_generated_bad_addr(alt_exception_cause cause);

#ifdef __cplusplus

}

#endif /* __cplusplus */

#endif /* __ALT_EXCEPTIONS_H__ */