altera_up_avalon_sram.v

基于Avalon的SDRAM控制器IP核

/*****************************************************************************
 *                                                                           *
 * Module:       Altera_UP_Avalon_SRAM                                       *
 * Description:                                                              *
 *      This module chipselects reads and writes to the sram, with 2-cycle   *
 *  read latency and one cycle write latency.                                *
 *                                                                           *
 *****************************************************************************/


module Altera_UP_Avalon_SRAM (
	// Inputs
	clk,
	reset,

	address,
	byteenable,
	chipselect,
	read,
	write,
	writedata,

	// Bi-Directional
	SRAM_DQ,

	// Outputs
	SRAM_ADDR,
	SRAM_LB_N,
	SRAM_UB_N,
	SRAM_CE_N,
	SRAM_OE_N,
	SRAM_WE_N,
	
	readdata
);


/*****************************************************************************
 *                           Parameter Declarations                          *
 *****************************************************************************/


/*****************************************************************************
 *                             Port Declarations                             *
 *****************************************************************************/
// Inputs
input				clk;
input				reset;

input		[17:0]	address;
input		[1:0]	byteenable;
input				chipselect;
input				read;
input				write;
input		[15:0]	writedata;

// Bi-Directional
inout		[15:0]	SRAM_DQ;		// SRAM Data bus 16 Bits

// Outputs
output	reg	[17:0]	SRAM_ADDR;		// SRAM Address bus 18 Bits
output	reg			SRAM_LB_N;		// SRAM Low-byte Data Mask 
output	reg			SRAM_UB_N;		// SRAM High-byte Data Mask 
output	reg			SRAM_CE_N;		// SRAM Chip chipselect
output	reg			SRAM_OE_N;		// SRAM Output chipselect
output	reg			SRAM_WE_N;		// SRAM Write chipselect

output	reg	[15:0]	readdata;

/*****************************************************************************
 *                 Internal Wires and Registers Declarations                 *
 *****************************************************************************/
// Internal Wires

// Internal Registers
reg			[15:0]	writedata_reg;

// State Machine Registers

/*****************************************************************************
 *                            Output assignments                             *
 *****************************************************************************/

assign SRAM_DQ