/*
 
 
 
reset...init...save.start_write.stop_write.restore.start_read(compare).stop_read.loop
 
 
 
*/
 
 
 
module mem_tester(
 
 
 
    clk,
 
 
 
    rst_n,
 
 
 
// pass/fail counters
 
    pass_counter,
 
    fail_counter,
 
 
 
// DRAM signals
 
    DRAM_DQ,
 
 
 
    DRAM_MA,
 
 
 
    DRAM_RAS0_N,
 
    DRAM_RAS1_N,
 
    DRAM_LCAS_N,
 
    DRAM_UCAS_N,
 
    DRAM_WE_N
 
);
 
 
 
parameter DRAM_DATA_SIZE = 16;
 
parameter DRAM_MA_SIZE = 10;
 
 
 
    inout [DRAM_DATA_SIZE-1:0] DRAM_DQ;
 
    output [DRAM_MA_SIZE-1:0] DRAM_MA;
 
    output DRAM_RAS0_N,DRAM_RAS1_N,DRAM_LCAS_N,DRAM_UCAS_N,DRAM_WE_N;
 
 
 
    input clk;
 
 
 
    input rst_n;
 
 
 
 
 
 
 
    reg inc_pass_ctr;
 
    reg inc_err_ctr;
 
 
 
    reg check_in_progress; // when 1 - enables errors checking
 
 
 
 
 
//----
 
 
 
    reg [15:0] pass_counter;
 
    output [15:0] pass_counter;
 
    reg [15:0] fail_counter;
 
    output [15:0] fail_counter;
 
    reg was_error;
 
 
 
    always @(posedge clk, negedge rst_n)
 
    begin
 
        if( !rst_n )
 
        begin
 
            pass_counter <= 16'd0;
 
            fail_counter <= 16'd0;
 
        end
 
        else if( inc_pass_ctr )
 
        begin
 
            if( (!was_error)&&(pass_counter!=16'hffff) )
 
                pass_counter <= pass_counter + 16'd1;
 
            if( (was_error)&&(fail_counter!=16'hffff) )
 
                fail_counter <= fail_counter + 16'd1;
 
            was_error <= 1'b0;
 
        end
 
        else if( inc_err_ctr )
 
            was_error <= 1'b1;
 
    end
 
 
 
//----
 
 
 
 
 
 
 
    reg rnd_init,rnd_save,rnd_restore; // rnd_vec_gen control
 
    wire [DRAM_DATA_SIZE-1:0] rnd_out; // rnd_vec_gen output
 
 
 
    rnd_vec_gen my_rnd( .clk(clk), .init(rnd_init), .next(ram_ready), .save(rnd_save), .restore(rnd_restore), .out(rnd_out) );
 
    defparam my_rnd.OUT_SIZE = DRAM_DATA_SIZE;
 
 
 
    defparam my_rnd.LFSR_LENGTH = 17;
 
    defparam my_rnd.LFSR_FEEDBACK = 14;
 
 
 
 
 
 
 
 
 
    reg ram_start,ram_rnw;
 
    wire ram_stop,ram_ready;
 
    wire [DRAM_DATA_SIZE-1:0] ram_rdat;
 
 
 
    dram_control my_ram( .clk(clk), .start(ram_start), .rnw(ram_rnw), .stop(ram_stop), .ready(ram_ready),
 
                         .rdat(ram_rdat), .wdat(rnd_out),
 
                         .DRAM_DQ(DRAM_DQ), .DRAM_MA(DRAM_MA), .DRAM_RAS0_N(DRAM_RAS0_N), .DRAM_RAS1_N(DRAM_RAS1_N),
 
                         .DRAM_LCAS_N(DRAM_LCAS_N), .DRAM_UCAS_N(DRAM_UCAS_N), .DRAM_WE_N(DRAM_WE_N) );
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
// FSM states and registers
 
    reg [3:0] curr_state,next_state;
 
 
 
parameter RESET        = 4'h0;
 
 
 
parameter INIT1        = 4'h1;
 
parameter INIT2        = 4'h2;
 
 
 
parameter BEGIN_WRITE1 = 4'h3;
 
parameter BEGIN_WRITE2 = 4'h4;
 
parameter BEGIN_WRITE3 = 4'h5;
 
parameter BEGIN_WRITE4 = 4'h6;
 
 
 
parameter WRITE        = 4'h7;
 
 
 
parameter BEGIN_READ1  = 4'h8;
 
parameter BEGIN_READ2  = 4'h9;
 
parameter BEGIN_READ3  = 4'hA;
 
parameter BEGIN_READ4  = 4'hB;
 
 
 
parameter READ         = 4'hC;
 
 
 
parameter END_READ     = 4'hD;
 
 
 
parameter INC_PASSES1  = 4'hE;
 
parameter INC_PASSES2  = 4'hF;
 
 
 
 
 
// FSM dispatcher
 
 
 
    always @*
 
    begin
 
        case( curr_state )
 
 
 
        RESET:
 
            next_state <= INIT1;
 
 
 
        INIT1:
 
                next_state <= INIT2;
 
 
 
        INIT2:
 
            if( ram_stop )
 
                next_state <= BEGIN_WRITE1;
 
            else
 
                next_state <= INIT2;
 
 
 
        BEGIN_WRITE1:
 
            next_state <= BEGIN_WRITE2;
 
 
 
        BEGIN_WRITE2:
 
            next_state <= BEGIN_WRITE3;
 
 
 
        BEGIN_WRITE3:
 
            next_state <= BEGIN_WRITE4;
 
 
 
        BEGIN_WRITE4:
 
            if( ram_stop )
 
                next_state <= BEGIN_WRITE4;
 
            else
 
                next_state <= WRITE;
 
 
 
        WRITE:
 
            if( ram_stop )
 
                next_state <= BEGIN_READ1;
 
            else
 
                next_state <= WRITE;
 
 
 
        BEGIN_READ1:
 
            next_state <= BEGIN_READ2;
 
 
 
        BEGIN_READ2:
 
            next_state <= BEGIN_READ3;
 
 
 
        BEGIN_READ3:
 
            next_state <= BEGIN_READ4;
 
 
 
        BEGIN_READ4:
 
            if( ram_stop )
 
                next_state <= BEGIN_READ4;
 
            else
 
                next_state <= READ;
 
 
 
        READ:
 
            if( ram_stop )
 
                next_state <= END_READ;
 
            else
 
                next_state <= READ;
 
 
 
        END_READ:
 
            next_state <= INC_PASSES1;
 
 
 
        INC_PASSES1:
 
            next_state <= INC_PASSES2;
 
 
 
        INC_PASSES2:
 
            next_state <= BEGIN_WRITE1;
 
 
 
 
 
 
 
 
 
        default:
 
            next_state <= RESET;
 
 
 
 
 
        endcase
 
    end
 
 
 
 
 
// FSM sequencer
 
 
 
    always @(posedge clk,negedge rst_n)
 
    begin
 
        if( !rst_n )
 
            curr_state <= RESET;
 
        else
 
            curr_state <= next_state;
 
    end
 
 
 
 
 
// FSM controller
 
 
 
    always @(posedge clk)
 
    begin
 
        case( curr_state )
 
 
 
//////////////////////////////////////////////////
 
        RESET:
 
        begin
 
            // various initializings begin
 
 
 
            inc_pass_ctr <= 1'b0;
 
            check_in_progress <= 1'b0;
 
            rnd_init <= 1'b1; //begin RND init
 
            rnd_save <= 1'b0;
 
            rnd_restore <= 1'b0;
 
            ram_start <= 1'b1;
 
            ram_rnw   <= 1'b1;
 
        end
 
 
 
        INIT1:
 
        begin
 
            rnd_init <= 1'b0; // end rnd init
 
            ram_start <= 1'b0;
 
        end
 
 
 
        INIT2:
 
        begin
 
        end
 
 
 
 
 
 
 
//////////////////////////////////////////////////
 
        BEGIN_WRITE1:
 
        begin
 
            rnd_save <= 1'b1;
 
        end
 
 
 
        BEGIN_WRITE2:
 
        begin
 
            rnd_save   <= 1'b0;
 
            ram_start <= 1'b1;
 
            ram_rnw   <= 1'b0;
 
        end
 
 
 
        BEGIN_WRITE3:
 
        begin
 
            ram_start <= 1'b0;
 
        end
 
 
 
/*      BEGIN_WRITE4:
 
        begin
 
            rnd_save   <= 1'b0;
 
            ram_start <= 1'b1;
 
        end
 
*/
 
/*      WRITE:
 
        begin
 
            ram_start <= 1'b0;
 
        end
 
*/
 
 
 
 
 
 
 
//////////////////////////////////////////////////
 
        BEGIN_READ1:
 
        begin
 
            rnd_restore <= 1'b1;
 
        end
 
 
 
        BEGIN_READ2:
 
        begin
 
            rnd_restore <= 1'b0;
 
            ram_start <= 1'b1;
 
            ram_rnw <= 1'b1;
 
        end
 
 
 
        BEGIN_READ3:
 
        begin
 
                ram_start <= 1'b0;
 
        end
 
 
 
        BEGIN_READ4:
 
        begin
 
                check_in_progress <= 1'b1;
 
        end
 
/*
 
        READ:
 
        begin
 
            ram_start <= 1'b0;
 
            check_in_progress <= 1'b1;
 
        end
 
*/
 
        END_READ:
 
        begin
 
            check_in_progress <= 1'b0;
 
        end
 
 
 
        INC_PASSES1:
 
        begin
 
            inc_pass_ctr <= 1'b1;
 
        end
 
 
 
        INC_PASSES2:
 
        begin
 
            inc_pass_ctr <= 1'b0;
 
        end
 
 
 
 
 
 
 
 
 
        endcase
 
    end
 
 
 
 
 
 
 
 
 
 
 
    always @(posedge clk)
 
        inc_err_ctr <= check_in_progress & ram_ready & ((ram_rdat==rnd_out) ? 1'b0: 1'b1);
 
 
 
 
 
 
 
endmodule