Subversion Repositories openrisc_2011-10-31

// Wrapper for Actel flash ROM

// 2 cycles from request to ACK

module flashrom(

                wb_clk,

                wb_rst,

                wb_adr_i,

                wb_cyc_i,

                wb_stb_i,

                wb_ack_o,

                wb_dat_o,

                wb_err_o,

                wb_rty_o);

   input wb_clk;

   input wb_rst;

   input [6:0] wb_adr_i;

   input       wb_cyc_i;

   input       wb_stb_i;

   output      wb_ack_o;

   output reg [7:0] wb_dat_o;

   output           wb_err_o;

   output           wb_rty_o;

   reg [3:0]         ack_shr;

   reg [6:0]         addr;

   wire [7:0]        dat;

   reg [7:0]         dat_r;

   wire             wb_access;

   assign wb_access = wb_cyc_i & wb_stb_i;

   always @(posedge wb_clk)

     if (wb_rst)

       ack_shr <= 0;

     else if (wb_access & !(|ack_shr))

       ack_shr[0] <= 1'b1;

     else

       ack_shr <= {ack_shr[2:0],1'b0};

   assign wb_ack_o = ack_shr[3];

   always @(posedge wb_clk)

     if (wb_access & !(|ack_shr))

       addr <= wb_adr_i;

   orpsoc_flashROM orpsoc_flashROM0

     (

      .CLK(wb_clk),

      .ADDR(addr),

      .DOUT(dat)

      );

   always @(posedge wb_clk)

     dat_r <= dat;

   always @(posedge wb_clk)

     wb_dat_o <= dat_r;

   assign wb_err_o = 0;

   assign wb_rty_o = 0;

endmodule // flashrom