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[/] [amber/] [trunk/] [hw/] [vlog/] [system/] [wb_xs6_ddr3_bridge.v] - Rev 15
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////////////////////////////////////////////////////////////////// // // // Wishbone Slave to Xilinx Spartan-6 MCB (DDR3 controller) // // Bridge // // // // This file is part of the Amber project // // http://www.opencores.org/project,amber // // // // Description // // Converts wishbone read and write accesses to the signalling // // used by the Xilinx DDR3 Controller in Spartan-6 FPGAs. // // // // The MCB is configured with a single 128-bit port. // // // // Author(s): // // - Conor Santifort, csantifort.amber@gmail.com // // // ////////////////////////////////////////////////////////////////// // // // Copyright (C) 2010 Authors and OPENCORES.ORG // // // // This source file may be used and distributed without // // restriction provided that this copyright statement is not // // removed from the file and that any derivative work contains // // the original copyright notice and the associated disclaimer. // // // // This source file is free software; you can redistribute it // // and/or modify it under the terms of the GNU Lesser General // // Public License as published by the Free Software Foundation; // // either version 2.1 of the License, or (at your option) any // // later version. // // // // This source is distributed in the hope that it will be // // useful, but WITHOUT ANY WARRANTY; without even the implied // // warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR // // PURPOSE. See the GNU Lesser General Public License for more // // details. // // // // You should have received a copy of the GNU Lesser General // // Public License along with this source; if not, download it // // from http://www.opencores.org/lgpl.shtml // // // ////////////////////////////////////////////////////////////////// module wb_xs6_ddr3_bridge ( input i_clk, input i_mem_ctrl, // 0=128MB, 1=32MB // Wishbone Bus input [31:0] i_wb_adr, input [3:0] i_wb_sel, input i_wb_we, output reg [31:0] o_wb_dat = 'd0, input [31:0] i_wb_dat, input i_wb_cyc, input i_wb_stb, output o_wb_ack, output o_wb_err, output o_cmd_en, // Command Enable output reg [2:0] o_cmd_instr = 'd0, // write = 000, read = 001 output reg [29:0] o_cmd_byte_addr = 'd0, // Memory address input i_cmd_full, // DDR3 I/F Command FIFO is full input i_wr_full, // DDR3 I/F Write Data FIFO is full output o_wr_en, // Write data enable output reg [15:0] o_wr_mask = 'd0, // 1 bit per byte output reg [127:0] o_wr_data = 'd0, // 16 bytes write data input [127:0] i_rd_data, // 16 bytes of read data input i_rd_empty // low when read data is valid ); wire start_write; wire start_read; reg start_write_d1; reg start_read_d1; reg start_read_hold = 'd0; reg [29:0] wb_adr_d1; wire ddr3_busy; reg read_ack = 'd0; reg read_ready = 1'd1; reg cmd_en_r = 'd0; reg wr_en_r = 'd0; assign start_write = i_wb_stb && i_wb_we && !start_read_d1; assign start_read = i_wb_stb && !i_wb_we && read_ready; assign ddr3_busy = i_cmd_full;// || i_wr_full; assign o_wb_err = 'd0; // ------------------------------------------------------ // Outputs // ------------------------------------------------------ // Command FIFO always @( posedge i_clk ) if ( !ddr3_busy ) begin o_cmd_byte_addr <= {wb_adr_d1[29:4], 4'd0}; cmd_en_r <= ( start_write_d1 || start_read_d1 ); o_cmd_instr <= start_write_d1 ? 3'd0 : 3'd1; end assign o_cmd_en = cmd_en_r && !i_cmd_full; // ------------------------------------------------------ // Write // ------------------------------------------------------ always @( posedge i_clk ) if ( !ddr3_busy ) begin wr_en_r <= start_write; o_wr_mask <= i_wb_adr[3:2] == 2'd0 ? { 12'hfff, ~i_wb_sel } : i_wb_adr[3:2] == 2'd1 ? { 8'hff, ~i_wb_sel, 4'hf } : i_wb_adr[3:2] == 2'd2 ? { 4'hf, ~i_wb_sel, 8'hff } : { ~i_wb_sel, 12'hfff } ; o_wr_data <= {4{i_wb_dat}}; end assign o_wr_en = wr_en_r && !i_cmd_full; // ------------------------------------------------------ // Read // ------------------------------------------------------ always @( posedge i_clk ) begin if ( read_ack ) read_ready <= 1'd1; else if ( start_read ) read_ready <= 1'd0; if ( !ddr3_busy ) begin start_write_d1 <= start_write; start_read_d1 <= start_read; wb_adr_d1 <= i_mem_ctrl ? {5'd0, i_wb_adr[24:0]} : i_wb_adr[29:0]; end if ( start_read ) start_read_hold <= 1'd1; else if ( read_ack ) start_read_hold <= 1'd0; if ( i_rd_empty == 1'd0 && start_read_hold ) begin o_wb_dat <= i_wb_adr[3:2] == 2'd0 ? i_rd_data[ 31: 0] : i_wb_adr[3:2] == 2'd1 ? i_rd_data[ 63:32] : i_wb_adr[3:2] == 2'd2 ? i_rd_data[ 95:64] : i_rd_data[127:96] ; read_ack <= 1'd1; end else read_ack <= 1'd0; end assign o_wb_ack = i_wb_stb && ( start_write || read_ack ) && !i_cmd_full; endmodule
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