component for dram

[raggedstone] / dhwk_old / source / pcidmux.v

// Copyright (C) 2005 Peio Azkarate, peio@opencores.org\r
// Copyright (C) 2006 Jeff Carr, jcarr@opencores.org\r
//\r
// I think what this does is handle 16 vs 32 bit pci accesses\r
\r
module pcidmux ( clk_i, nrst_i, d_io, pcidatout_o, pcidOE_i, wbdatLD_i, wbrgdMX_i,\r
	wbd16MX_i, wb_dat_i, wb_dat_o, rg_dat_i, rg_dat_o);\r
\r
	input clk_i;\r
	input nrst_i;\r
\r
	// d_io			: inout std_logic_vector(31 downto 0);\r
	inout [31:0] d_io;\r
	output [31:0] pcidatout_o;\r
\r
	input pcidOE_i;\r
	input wbdatLD_i;\r
	input wbrgdMX_i;\r
	input wbd16MX_i;\r
\r
	input [15:0] wb_dat_i;\r
	output [15:0] wb_dat_o;\r
	input [31:0] rg_dat_i;\r
	output [31:0] rg_dat_o;\r
\r
  	wire [31:0] pcidatin;\r
  	wire [31:0] pcidatout;\r
\r
  	reg [15:0] wb_dat_is;\r
\r
	// always @(negedge nrst_i or posedge clk_i or posedge wbdatLD_i or posedge wb_dat_i)\r
	always @(negedge nrst_i or posedge clk_i)\r
	begin\r
		if ( nrst_i == 0 )\r
			wb_dat_is <= 16'b1111_1111_1111_1111;\r
		else\r
			if ( wbdatLD_i == 1 )\r
				wb_dat_is <= wb_dat_i;\r
	end\r
\r
	assign pcidatin = d_io;\r
	assign d_io = (pcidOE_i == 1'b1 ) ? pcidatout : 32'bZ;\r
\r
	assign pcidatout [31:24] = (wbrgdMX_i == 1'b1) ? wb_dat_is [7:0]  : rg_dat_i [31:24];\r
	assign pcidatout [23:16] = (wbrgdMX_i == 1'b1) ? wb_dat_is [15:8] : rg_dat_i [23:16];\r
	assign pcidatout [15:8]  = (wbrgdMX_i == 1'b1) ? wb_dat_is [7:0]  : rg_dat_i [15:8];\r
	assign pcidatout [7:0]   = (wbrgdMX_i == 1'b1) ? wb_dat_is [15:8] : rg_dat_i [7:0];\r
\r
	assign pcidatout_o = pcidatout;\r
	assign rg_dat_o = pcidatin;\r
\r
	assign wb_dat_o [15:8] = (wbd16MX_i == 1'b1) ? pcidatin [23:16] : pcidatin [7:0];\r
	assign wb_dat_o [7:0]  = (wbd16MX_i == 1'b1) ? pcidatin [31:24] : pcidatin [15:8];\r
\r
endmodule \r