initial begin:test
    //ck     <= 1'b0;
    cke    <= 1'b0;
    cs_n   <= 1'bz;
    ras_n  <= 1'bz;
    cas_n  <= 1'bz;
    we_n   <= 1'bz;
    a      <= {ADDR_BITS{1'bz}}; 
    ba     <= {BA_BITS{1'bz}};
    dq_en  <= 1'b0;
    dqs_en <= 1'b0;
    power_up;
    nop (10); // wait 10 clocks intead of 200 us for simulation purposes
    precharge('h00000000, 1);
    nop(trp);
    refresh;
    nop(trfc);
    refresh;
    nop(trfc);
    load_mode('h0, 'h00000032);
    nop(tmrd);
    load_mode('h2, 'h00004000);
    nop(tmrd);
    activate('h00000000, 'h00000000);
    nop(trcd-1);
    write('h00000000, 'h00000000, 0, { {DM_BITS{1'b0}}, {DM_BITS{1'b0}}, {DM_BITS{1'b0}}, {DM_BITS{1'b0}}}, { 16'h3000, 16'h2000, 16'h1000, 16'h0});
    nop(bl/2+twr);
    read('h00000000, 'h00000000, 1);
    nop(bl/2-1);
    nop('h00000014);
    test_done;
end