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// ----------------------------------------------------------------------------
 
// SystemC OpenRISC 1000 Debug Unit: definition
 
// Copyright (C) 2008  Embecosm Limited <info@embecosm.com>
 
// Contributor Jeremy Bennett <jeremy.bennett@embecosm.com>
 
// This file is part of the GDB interface to the cycle accurate model of the
// OpenRISC 1000 based system-on-chip, ORPSoC, built using Verilator.
 
// This program is free software: you can redistribute it and/or modify it
// under the terms of the GNU Lesser 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 Lesser General Public
// License for more details.
 
// You should have received a copy of the GNU Lesser General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
// ----------------------------------------------------------------------------
 
// $Id$
 
#ifndef DEBUG_UNIT_SC__H
#define DEBUG_UNIT_SC__H
 
 
// Define if no cache is wanted
#define NOCACHE
 
#include <stdint.h>
 
#include "systemc"
 
#include "JtagSC_includes.h"
#include "OrpsocAccess.h"
#include "SprCache.h"
#include "MemCache.h"
 
 
//-----------------------------------------------------------------------------
//! Module modeling the OpenRISC 1000 Debug Unit
 
//! Provides a high level interface to the GDB Server module with functions to
//! access SPRs, Wishbone memory and CPU control.
 
//! Provides a low level interface to the Embecosm SystemC JTAG interface,
//! queueing requests to read and write JTAG registers.
//-----------------------------------------------------------------------------
class DebugUnitSC
  : public sc_core::sc_module
{
public:
 
  // Constructor and destructor
  DebugUnitSC (sc_core::sc_module_name        name,
	       sc_core::sc_fifo<TapAction *> *_tapActionQueue);
  ~DebugUnitSC ();
 
  // Reset function for the debug unit
  void      resetDebugUnit ();
 
  // Functions to control and report on the CPU
  void      reset ();
  void      stall ();
  void      unstall ();
  bool      isStalled ();
 
  // Functions to access SPRs
  uint32_t  readSpr (uint16_t  sprNum);
  void      writeSpr (uint16_t  sprNum,
		      uint32_t  value);
  void      andSpr (uint16_t  sprNum,
		    uint32_t  value);
  void      orSpr (uint16_t  sprNum,
		   uint32_t  value);
 
  // Functions to access memory
  uint32_t  readMem32 (uint32_t  addr);
  bool      writeMem32 (uint32_t  addr,
			uint32_t   value);
  uint8_t   readMem8 (uint32_t  addr);
  bool      writeMem8 (uint32_t  addr,
		       uint8_t   value);
 
private:
 
  // JTAG instructions
  static const uint32_t  CHAIN_SELECT_IR = 0x3;  //!< Chain Select instruction
  static const uint32_t  DEBUG_IR        = 0x8;  //!< Debug instruction
 
  //! JTAG instruction register length. There is no CRC for this register.
  static const int  JTAG_IR_LEN       =  4;	//!< JTAG instr reg length
 
  // DEBUG UNIT CHAIN data register fields
  static const int  DUSEL_DR_LEN     = 73;  //!< total DUSEL DR size
  static const int  DUSEL_SEL_OFF =  0;  //!< start of select field
  static const int  DUSEL_SEL_LEN =  1;  //!< length of select field
  static const int  DUSEL_OPCODE_OFF =  DUSEL_SEL_OFF + DUSEL_SEL_LEN;  //!< start of opcode field
  static const int  DUSEL_OPCODE_LEN =  4;  //!< length of opcode field
  static const int  DUSEL_CRC_OFF    =  DUSEL_OPCODE_OFF + DUSEL_OPCODE_LEN;  //!< start of CRC field
  static const int  DUSEL_CRC_LEN    = 32;  //!< length of CRC field
  static const int  DUSEL_RESP_STATUS_OFF = DUSEL_CRC_OFF + DUSEL_CRC_LEN;
  static const int  DUSEL_RESP_STATUS_LEN = 4;
  static const int  DUSEL_RESP_CRC_OFF = DUSEL_RESP_STATUS_OFF + DUSEL_RESP_STATUS_LEN;
  static const int  DUSEL_RESP_CRC_LEN = 32;
 
  static const uint32_t  DBG_CRC32_POLY = 0x04c11db7;
 
  // OpenRISC 1000 scan chains (values in DUSEL data register field)
  static const int  OR1K_SC_UNDEF      = -1;	//!< Undefined OR1K scan chain
  static const int  OR1K_SC_WISHBONE   =  0;	//!< for memory access
  static const int  OR1K_SC_CPU0 =  1;	        //!< for access to CPU0
  static const int  OR1K_SC_CPU1 =  2;	        //!< for access to CPU1
 
 
 
  // JTAG RISC_DEBUG (for accessing SPR) data register fields
  static const int  RISC_DEBUG_DR_LEN    = 74;	//!< Total RISC_DEBUG DR size
  static const int  RISC_DEBUG_ADDR_OFF  =  0;	//!< start of address field
  static const int  RISC_DEBUG_ADDR_LEN  = 32;	//!< length of address field
  static const int  RISC_DEBUG_RW_OFF    = 32;	//!< start of read/write field
  static const int  RISC_DEBUG_RW_LEN    =  1;	//!< length of read/write field
  static const int  RISC_DEBUG_DATA_OFF  = 33;	//!< start of data field
  static const int  RISC_DEBUG_DATA_LEN  = 32;	//!< length of data field
  static const int  RISC_DEBUG_CRC_OFF   = 65;	//!< start of CRC field
  static const int  RISC_DEBUG_CRC_LEN   =  8;	//!< length of CRC field
  static const int  RISC_DEBUG_SPARE_OFF = 73;	//!< start of spare bits
  static const int  RISC_DEBUG_SPARE_LEN =  1;	//!< length of spare bit field
 
  // JTAG REGISTER (for controlling the CPU) data register fields
  static const int  REGISTER_DR_LEN      = 47;	//!< Total REGISTER DR size
  static const int  REGISTER_ADDR_OFF    =  0;	//!< start of address field
  static const int  REGISTER_ADDR_LEN    =  5;	//!< length of address field
  static const int  REGISTER_RW_OFF      =  5;	//!< start of read/write field
  static const int  REGISTER_RW_LEN      =  1;	//!< length of read/write field
  static const int  REGISTER_DATA_OFF    =  6;	//!< start of data field
  static const int  REGISTER_DATA_LEN    = 32;	//!< length of data field
  static const int  REGISTER_CRC_OFF     = 38;	//!< start of CRC field
  static const int  REGISTER_CRC_LEN     =  8;	//!< length of CRC field
  static const int  REGISTER_SPARE_OFF   = 46;	//!< start of spare bits
  static const int  REGISTER_SPARE_LEN   =  1;	//!< length of spare bit field
 
  // Register addresses for the REGISTER scan chain
  static const uint8_t  OR1K_RSC_RISCOP = 0x04;	//!< Used to reset/stall CPU
 
  // Bits for the RISCOP register
  static const uint32_t  RISCOP_RESET = 0x00000001;	//!< Reset the CPU
  static const uint32_t  RISCOP_STALL = 0x00000002;	//!< Stall the CPU
 
  // JTAG WISHBONE (for accessing SPR) data register fields
  static const int  WISHBONE_DR_LEN      = 74;	//!< Total WISHBONE DR size
  static const int  WISHBONE_ADDR_OFF    =  0;	//!< start of address field
  static const int  WISHBONE_ADDR_LEN    = 32;	//!< length of address field
  static const int  WISHBONE_RW_OFF      = 32;	//!< start of read/write field
  static const int  WISHBONE_RW_LEN      =  1;	//!< length of read/write field
  static const int  WISHBONE_DATA_OFF    = 33;	//!< start of data field
  static const int  WISHBONE_DATA_LEN    = 32;	//!< length of data field
  static const int  WISHBONE_CRC_OFF     = 65;	//!< start of CRC field
  static const int  WISHBONE_CRC_LEN     =  8;	//!< length of CRC field
  static const int  WISHBONE_SPARE_OFF   = 73;	//!< start of spare bits
  static const int  WISHBONE_SPARE_LEN   =  1;	//!< length of spare bit field
 
  //! The NPC is special, so we need to know about it
  static const int  SPR_NPC = 0x10;
 
  //! The JTAG fifo we queue on
  sc_core::sc_fifo<TapAction *> *tapActionQueue;
 
  //! The processor stall state. When stalled we can use cacheing on
  //! reads/writes of memory and SPRs.
  enum {
    UNKNOWN,
    STALLED,
  } stallState;
 
  //! The currently selected scan chain
  int  currentScanChain;
 
#ifdef NOCACHE
  //! Even if no cached, we need to cache the NPC
  uint32_t  npcCachedValue;
 
  //! Cached NPC is valid
  bool  npcCacheIsValid;
 
#else
  //! The SPR cache
  SprCache *sprCache;
 
  //! The memory cache
  MemCache *memCache;
#endif
 
  // Functions to control the CPU
  uint32_t  readRiscop ();
  void      writeRiscop (uint32_t  value);
 
  // Or1k JTAG actions
  void      selectDebugModule (int chain);
  uint32_t  readJtagReg (uint32_t  addr);
  uint32_t  readJtagReg1 (uint32_t   addr,
			  int        bitSizeNoCrc);
  uint32_t  readJtagReg1 (uint64_t  *dRegArray,
			  uint32_t   addr,
			  int        bitSizeNoCrc);
  void      writeJtagReg (uint32_t  addr,
			  uint32_t  data);
 
  // Utilities to pack and unpack bits to/from data registers.
  void clearBits (uint64_t  regArray[],
		  int       regBits);
 
  void packBits (uint64_t  regArray[],
		 int       fieldOffset,
		 int       fieldBits,
		 uint64_t  fieldVal);
 
  uint64_t  unpackBits (uint64_t  regArray[],
			int       fieldOffset,
			int       fieldBits);
 
  // Utility to compute CRC-8 the OpenRISC way.
  uint8_t  crc8 (uint64_t  dataArray[],
		 int       size);
 
  // Utility to compute CRC-32 for the debug unit
  uint32_t  crc32 (uint64_t  dataArray[],
		   int       size,
		   int       offset);
 
  // Functions to bitreverse values
  uint32_t bit_reverse_swar_2(uint32_t x);
  uint32_t bit_reverse_swar_4(uint32_t x);
  uint32_t bit_reverse_swar_8(uint32_t x);
  uint32_t bit_reverse_swar_16(uint32_t x);
  uint32_t bit_reverse_swar_32(uint32_t x);
#define BITREV(x,y) bit_reverse_data(x,y)
  uint32_t bit_reverse_data(uint32_t x, int length);
 
 
 
};	// DebugUnitSC ()
 
#endif	// DEBUG_UNIT_SC__H