sdram.v

一些实用的sdramVHDL编程源码

`include "inc.h"

//*******************************************************************************
//  S Y N T H E Z I A B L E      S D R A M     C O N T R O L L E R    C O R E
//
//  This core adheres to the GNU Public License  
// 
//  This is a synthesizable Synchronous DRAM controller Core.  As it stands,
//  it is ready to work with 8Mbyte SDRAMs, organized as 2M x 32 at 100MHz
//  and 125MHz. For example: Samsung KM432S2030CT,  Fujitsu MB81F643242B.
//
//  The core has been carefully coded so as to be "platform-independent".  
//  It has been successfully compiled and simulated under three separate
//  FPGA/CPLD platforms:
//      Xilinx Foundation Base Express V2.1i
//      Altera Max+PlusII V9.21
//      Lattice ispExpert V7.0
//  
//  The interface to the host (i.e. microprocessor, DSP, etc) is synchronous
//  and supports ony one transfer at a time.  That is, burst-mode transfers
//  are not yet supported.  In may ways, the interface to this core is much
//  like that of a typical SRAM.  The hand-shaking between the host and the 
//  SDRAM core is done through the "sdram_busy_l" signal generated by the 
//  core.  Whenever this signal is active low, the host must hold the address,
//  data (if doing a write), size and the controls (cs, rd/wr).  
//
//  Connection Diagram:
//  SDRAM side:
//  sd_wr_l                     connect to -WR pin of SDRAM
//  sd_cs_l                     connect to -CS pin of SDRAM
//  sd_ras_l                    connect to -RAS pin of SDRAM
//  sd_cas_l                    connect to -CAS pin of SDRAM
//  sd_dqm[3:0]                 connect to the DQM3,DQM2,DQM1,DQM0 pins
//  sd_addx[10:0]               connect to the Address bus [10:0]
//  sd_data[31:0]               connect to the data bus [31:0]
//  sd_ba[1:0]                  connect to BA1, BA0 pins of SDRAM
//   
//  HOST side:
//  mp_addx[22:0]               connect to the address bus of the host. 
//                              23 bit address bus give access to 8Mbyte
//                              of the SDRAM, as byte, half-word (16bit)
//                              or word (32bit)
//  mp_data_in[31:0]            Unidirectional bus connected to the data out
//                              of the host. To use this, enable 
//                              "databus_is_unidirectional" in INC.H
//  mp_data_out[31:0]           Unidirectional bus connected to the data in 
//                              of the host.  To use this, enable
//                              "databus_is_unidirectional" in INC.H
//  mp_data[31:0]               Bi-directional bus connected to the host's
//                              data bus.  To use the bi-directionla bus,
//                              disable "databus_is_unidirectional" in INC.H
//  mp_rd_l                     Connect to the -RD output of the host
//  mp_wr_l                     Connect to the -WR output of the host
//  mp_cs_l                     Connect to the -CS of the host
//  mp_size[1:0]                Connect to the size output of the host
//                              if there is one.  When set to 0
//                              all trasnfers are 32 bits, when set to 1
//                              all transfers are 8 bits, and when set to
//                              2 all xfers are 16 bits.  If you want the
//                              data to be lower order aligned, turn on
//                              "align_data_bus" option in INC.H
//  sdram_busy_l                Connect this to the wait or hold equivalent
//                              input of the host.  The host, must hold the
//                              bus if it samples this signal as low.
//  sdram_mode_set_l            When a write occurs with this set low,
//                              the SDRAM's mode set register will be programmed
//                              with the data supplied on the data_bus[10:0].
//
//
//  Author:  Jeung Joon Lee  [e-mail],  [e-mail]
//  
//*******************************************************************************
//
//  Hierarchy:
//
//  SDRAM.V         Top Level Module
//  HOSTCONT.V      Controls the interfacing between the micro and the SDRAM
//  SDRAMCNT.V      This is the SDRAM controller.  All data passed to and from
//                  is with the HOSTCONT.
//  optional
//  MICRO.V         This is the built in SDRAM tester.  This module generates 
//                  a number of test logics which is used to test the SDRAM
//                  It is basically a Micro bus generator. 
//  
/*
*/ 



module sdram(
            // SYSTEM LEVEL CONNECTIONS
            sys_rst_l,
            sys_clk,
            // SDRAM CONNECTIONS
            sd_wr_l,
            sd_cs_l,
            sd_ras_l,
            sd_cas_l,
            sd_dqm,
            sd_addx,
            sd_data,
            sd_ba,
            // MICROPORCESSOR CONNECTION
            mp_addx
`ifdef databus_is_unidirectional
            ,
            mp_data_in,
            mp_data_out,
`else
            ,
            mp_data,
`endif
            mp_rd_l,
            mp_wr_l,
            mp_cs_l,
            sdram_mode_set_l,
            sdram_busy_l,
            mp_size,
            next_state
            
            // DEBUG
`ifdef show_debug
            ,            
            next_state,
            mp_data_out_sd,
            mp_data_gate
            do_write,
            reg_mp_addx,
            reg_mp_data_mux,
            sd_addx_mux,
            sd_addx10_mux,
            next_state,
            doing_refresh,
            do_modeset,
            do_read,
            sd_addx_mux,
            sd_addx10_mux,
            autorefresh_cntr,
            autorefresh_cntr_l,
            pwrup,
            top_state,
            wr_cntr,
            mp_data_micro,
            mp_data_mux,
            sd_data_ena,
            mp_data_out,
            sd_addx_mux,
            sd_addx10_mux,
            sd_rd_ena
`endif
 );





// ****************************************
//
//   I/O  DEFINITION
//
// ****************************************
// SYSTEM LEVEL CONNECTIONS
input           sys_clk;                // global system clock.  Runs the sdram state machine
input           sys_rst_l;              // global active low asynchronous system reset
// SDRAM CONNECTIONS
output          sd_wr_l;                // SDRAM active low WRITE signal
output          sd_cs_l;                // SDRAM active low chip select signal
output          sd_ras_l;               // SDRAM active low RAS 
output          sd_cas_l;               // SDRAM active low CAS
output  [3:0]   sd_dqm;                 // SDRAM data masks
output  [10:0]  sd_addx;                // SDRAM multiplexed address bus
inout   [31:0]  sd_data;                // SDRAM birectional data bus 32 bit
output  [1:0]   sd_ba;                  // SDRAM bank address , aka A11
// MICROPROCESSOR CONNECTION
`ifdef databus_is_unidirectional
input   [31:0]  mp_data_in;             
output  [31:0]  mp_data_out;
`else
`ifdef simulate_mp
inout   [31:0]  mp_data;
`else
output      [31:0]  mp_data;
`endif
`endif
`ifdef simulate_mp
output  [22:0]  mp_addx;                // HOST address bus. 23 bits for 8Mb
output          mp_rd_l;                // HOST active low READ 
output          mp_wr_l;                // HOST active low WRITE
output          mp_cs_l;                // HOST active low chip select
output          sdram_mode_set_l;
output  [1:0]   mp_size;                // 00=32bits, 10=16bits, 01=8bits
`else
input   [22:0]  mp_addx;                // HOST address bus. 23 bits for 8Mb
input           mp_rd_l;                // HOST active low READ 
input           mp_wr_l;                // HOST active low WRITE
input           mp_cs_l;                // HOST active low chip select
input           sdram_mode_set_l;
input   [1:0]   mp_size;                // 00=32bits, 10=16bits, 01=8bits
`endif
output          sdram_busy_l;
output  [3:0]   next_state;
// DEBUG
`ifdef show_debug
output  [31:0]  mp_data_out_sd;
output          mp_data_gate;
output          do_write;
output  [22:0]  reg_mp_addx;
output  [31:0]  reg_mp_data_mux;
output          sd_addx_mux;
output          sd_addx10_mux;
output          do_modeset;
output          do_read;
output          doing_refresh;
output  [3:0]   next_state;
output  [12:0]  autorefresh_cntr;
output          autorefresh_cntr_l;
output          pwrup;
output  [3:0]   top_state;
output  [7:0]   wr_cntr;
//output[31:0]  mp_data_micro;
output  [31:0]  mp_data_out;
//output        mp_data_mux;
output          sd_data_ena;
output          sd_rd_ena;
`endif


// INTER-MODULE CONNECTIONS
wire            do_modeset;
wire            do_read;
wire            do_write;
wire            doing_refresh;
wire            sd_addx_ena;
wire    [1:0]   sd_addx_mux;
wire    [1:0]   sd_addx10_mux;
wire            sd_rd_ena;
wire            sd_data_ena;
wire    [2:0]   modereg_cas_latency;
wire    [2:0]   modereg_burst_length;
wire    [3:0]   next_state;
wire    [31:0]  mp_data_out_sd;
wire    [31:0]  mp_data_in;