/* Copyright (c) 2018 Alex Forencich Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ // Language: Verilog 2001 `timescale 1ns / 1ps /* * AXI4-Lite dual port RAM */ module axil_dp_ram # ( parameter DATA_WIDTH = 32, // width of data bus in bits parameter ADDR_WIDTH = 16, // width of address bus in bits parameter STRB_WIDTH = (DATA_WIDTH/8), parameter PIPELINE_OUTPUT = 0 ) ( input wire a_clk, input wire a_rst, input wire b_clk, input wire b_rst, input wire [ADDR_WIDTH-1:0] s_axil_a_awaddr, input wire [2:0] s_axil_a_awprot, input wire s_axil_a_awvalid, output wire s_axil_a_awready, input wire [DATA_WIDTH-1:0] s_axil_a_wdata, input wire [STRB_WIDTH-1:0] s_axil_a_wstrb, input wire s_axil_a_wvalid, output wire s_axil_a_wready, output wire [1:0] s_axil_a_bresp, output wire s_axil_a_bvalid, input wire s_axil_a_bready, input wire [ADDR_WIDTH-1:0] s_axil_a_araddr, input wire [2:0] s_axil_a_arprot, input wire s_axil_a_arvalid, output wire s_axil_a_arready, output wire [DATA_WIDTH-1:0] s_axil_a_rdata, output wire [1:0] s_axil_a_rresp, output wire s_axil_a_rvalid, input wire s_axil_a_rready, input wire [ADDR_WIDTH-1:0] s_axil_b_awaddr, input wire [2:0] s_axil_b_awprot, input wire s_axil_b_awvalid, output wire s_axil_b_awready, input wire [DATA_WIDTH-1:0] s_axil_b_wdata, input wire [STRB_WIDTH-1:0] s_axil_b_wstrb, input wire s_axil_b_wvalid, output wire s_axil_b_wready, output wire [1:0] s_axil_b_bresp, output wire s_axil_b_bvalid, input wire s_axil_b_bready, input wire [ADDR_WIDTH-1:0] s_axil_b_araddr, input wire [2:0] s_axil_b_arprot, input wire s_axil_b_arvalid, output wire s_axil_b_arready, output wire [DATA_WIDTH-1:0] s_axil_b_rdata, output wire [1:0] s_axil_b_rresp, output wire s_axil_b_rvalid, input wire s_axil_b_rready ); parameter VALID_ADDR_WIDTH = ADDR_WIDTH - $clog2(STRB_WIDTH); parameter WORD_WIDTH = STRB_WIDTH; parameter WORD_SIZE = DATA_WIDTH/WORD_WIDTH; reg read_eligible_a; reg write_eligible_a; reg read_eligible_b; reg write_eligible_b; reg mem_wr_en_a; reg mem_rd_en_a; reg mem_wr_en_b; reg mem_rd_en_b; reg last_read_a_reg = 1'b0, last_read_a_next; reg last_read_b_reg = 1'b0, last_read_b_next; reg s_axil_a_awready_reg = 1'b0, s_axil_a_awready_next; reg s_axil_a_wready_reg = 1'b0, s_axil_a_wready_next; reg [1:0] s_axil_a_bresp_reg = 2'b00, s_axil_a_bresp_next; reg s_axil_a_bvalid_reg = 1'b0, s_axil_a_bvalid_next; reg s_axil_a_arready_reg = 1'b0, s_axil_a_arready_next; reg [DATA_WIDTH-1:0] s_axil_a_rdata_reg = {DATA_WIDTH{1'b0}}, s_axil_a_rdata_next; reg [1:0] s_axil_a_rresp_reg = 2'b00, s_axil_a_rresp_next; reg s_axil_a_rvalid_reg = 1'b0, s_axil_a_rvalid_next; reg [DATA_WIDTH-1:0] s_axil_a_rdata_pipe_reg = {DATA_WIDTH{1'b0}}; reg [1:0] s_axil_a_rresp_pipe_reg = 2'b00; reg s_axil_a_rvalid_pipe_reg = 1'b0; reg s_axil_b_awready_reg = 1'b0, s_axil_b_awready_next; reg s_axil_b_wready_reg = 1'b0, s_axil_b_wready_next; reg [1:0] s_axil_b_bresp_reg = 2'b00, s_axil_b_bresp_next; reg s_axil_b_bvalid_reg = 1'b0, s_axil_b_bvalid_next; reg s_axil_b_arready_reg = 1'b0, s_axil_b_arready_next; reg [DATA_WIDTH-1:0] s_axil_b_rdata_reg = {DATA_WIDTH{1'b0}}, s_axil_b_rdata_next; reg [1:0] s_axil_b_rresp_reg = 2'b00, s_axil_b_rresp_next; reg s_axil_b_rvalid_reg = 1'b0, s_axil_b_rvalid_next; reg [DATA_WIDTH-1:0] s_axil_b_rdata_pipe_reg = {DATA_WIDTH{1'b0}}; reg [1:0] s_axil_b_rresp_pipe_reg = 2'b00; reg s_axil_b_rvalid_pipe_reg = 1'b0; // (* RAM_STYLE="BLOCK" *) reg [DATA_WIDTH-1:0] mem[(2**VALID_ADDR_WIDTH)-1:0]; wire [VALID_ADDR_WIDTH-1:0] s_axil_a_awaddr_valid = s_axil_a_awaddr >> (ADDR_WIDTH - VALID_ADDR_WIDTH); wire [VALID_ADDR_WIDTH-1:0] s_axil_a_araddr_valid = s_axil_a_araddr >> (ADDR_WIDTH - VALID_ADDR_WIDTH); wire [VALID_ADDR_WIDTH-1:0] s_axil_b_awaddr_valid = s_axil_b_awaddr >> (ADDR_WIDTH - VALID_ADDR_WIDTH); wire [VALID_ADDR_WIDTH-1:0] s_axil_b_araddr_valid = s_axil_b_araddr >> (ADDR_WIDTH - VALID_ADDR_WIDTH); assign s_axil_a_awready = s_axil_a_awready_reg; assign s_axil_a_wready = s_axil_a_wready_reg; assign s_axil_a_bresp = s_axil_a_bresp_reg; assign s_axil_a_bvalid = s_axil_a_bvalid_reg; assign s_axil_a_arready = s_axil_a_arready_reg; assign s_axil_a_rdata = PIPELINE_OUTPUT ? s_axil_a_rdata_pipe_reg : s_axil_a_rdata_reg; assign s_axil_a_rresp = PIPELINE_OUTPUT ? s_axil_a_rresp_pipe_reg : s_axil_a_rresp_reg; assign s_axil_a_rvalid = PIPELINE_OUTPUT ? s_axil_a_rvalid_pipe_reg : s_axil_a_rvalid_reg; assign s_axil_b_awready = s_axil_b_awready_reg; assign s_axil_b_wready = s_axil_b_wready_reg; assign s_axil_b_bresp = s_axil_b_bresp_reg; assign s_axil_b_bvalid = s_axil_b_bvalid_reg; assign s_axil_b_arready = s_axil_b_arready_reg; assign s_axil_b_rdata = PIPELINE_OUTPUT ? s_axil_b_rdata_pipe_reg : s_axil_b_rdata_reg; assign s_axil_b_rresp = PIPELINE_OUTPUT ? s_axil_b_rresp_pipe_reg : s_axil_b_rresp_reg; assign s_axil_b_rvalid = PIPELINE_OUTPUT ? s_axil_b_rvalid_pipe_reg : s_axil_b_rvalid_reg; integer i, j; initial begin // two nested loops for smaller number of iterations per loop // workaround for synthesizer complaints about large loop counts for (i = 0; i < 2**ADDR_WIDTH; i = i + 2**(ADDR_WIDTH/2)) begin for (j = i; j < i + 2**(ADDR_WIDTH/2); j = j + 1) begin mem[j] = 0; end end end always @* begin mem_wr_en_a = 1'b0; mem_rd_en_a = 1'b0; last_read_a_next = last_read_a_reg; s_axil_a_awready_next = 1'b0; s_axil_a_wready_next = 1'b0; s_axil_a_bresp_next = 2'b00; s_axil_a_bvalid_next = s_axil_a_bvalid_reg && !s_axil_a_bready; s_axil_a_arready_next = 1'b0; s_axil_a_rresp_next = 2'b00; s_axil_a_rvalid_next = s_axil_a_rvalid_reg && !(s_axil_a_rready || (PIPELINE_OUTPUT && !s_axil_a_rvalid_pipe_reg)); write_eligible_a = s_axil_a_awvalid && s_axil_a_wvalid && (!s_axil_a_bvalid || s_axil_a_bready) && (!s_axil_a_awready && !s_axil_a_wready); read_eligible_a = s_axil_a_arvalid && (!s_axil_a_rvalid || s_axil_a_rready || (PIPELINE_OUTPUT && !s_axil_a_rvalid_pipe_reg)) && (!s_axil_a_arready); if (write_eligible_a && (!read_eligible_a || last_read_a_reg)) begin last_read_a_next = 1'b0; s_axil_a_awready_next = 1'b1; s_axil_a_wready_next = 1'b1; s_axil_a_bresp_next = 2'b00; s_axil_a_bvalid_next = 1'b1; mem_wr_en_a = 1'b1; end else if (read_eligible_a) begin last_read_a_next = 1'b1; s_axil_a_arready_next = 1'b1; s_axil_a_rresp_next = 2'b00; s_axil_a_rvalid_next = 1'b1; mem_rd_en_a = 1'b1; end end always @(posedge a_clk) begin if (a_rst) begin last_read_a_reg <= 1'b0; s_axil_a_awready_reg <= 1'b0; s_axil_a_wready_reg <= 1'b0; s_axil_a_bvalid_reg <= 1'b0; s_axil_a_arready_reg <= 1'b0; s_axil_a_rresp_reg <= 2'b00; s_axil_a_rvalid_reg <= 1'b0; s_axil_a_rvalid_pipe_reg <= 1'b0; end else begin last_read_a_reg <= last_read_a_next; s_axil_a_awready_reg <= s_axil_a_awready_next; s_axil_a_wready_reg <= s_axil_a_wready_next; s_axil_a_bvalid_reg <= s_axil_a_bvalid_next; s_axil_a_arready_reg <= s_axil_a_arready_next; s_axil_a_rresp_reg <= s_axil_a_rresp_next; s_axil_a_rvalid_reg <= s_axil_a_rvalid_next; if (!s_axil_a_rvalid_pipe_reg || s_axil_a_rready) begin s_axil_a_rvalid_pipe_reg <= s_axil_a_rvalid_reg; end end s_axil_a_bresp_reg <= s_axil_a_bresp_next; if (mem_rd_en_a) begin s_axil_a_rdata_reg <= mem[s_axil_a_araddr_valid]; end else begin for (i = 0; i < WORD_WIDTH; i = i + 1) begin if (mem_wr_en_a && s_axil_a_wstrb[i]) begin mem[s_axil_a_awaddr_valid][8*i +: 8] <= s_axil_a_wdata[8*i +: 8]; end end end if (!s_axil_a_rvalid_pipe_reg || s_axil_a_rready) begin s_axil_a_rdata_pipe_reg <= s_axil_a_rdata_reg; s_axil_a_rresp_pipe_reg <= s_axil_a_rresp_reg; end end always @* begin mem_wr_en_b = 1'b0; mem_rd_en_b = 1'b0; last_read_b_next = last_read_b_reg; s_axil_b_awready_next = 1'b0; s_axil_b_wready_next = 1'b0; s_axil_b_bresp_next = 2'b00; s_axil_b_bvalid_next = s_axil_b_bvalid_reg && !s_axil_b_bready; s_axil_b_arready_next = 1'b0; s_axil_b_rresp_next = 2'b00; s_axil_b_rvalid_next = s_axil_b_rvalid_reg && !(s_axil_b_rready || (PIPELINE_OUTPUT && !s_axil_b_rvalid_pipe_reg)); write_eligible_b = s_axil_b_awvalid && s_axil_b_wvalid && (!s_axil_b_bvalid || s_axil_b_bready) && (!s_axil_b_awready && !s_axil_b_wready); read_eligible_b = s_axil_b_arvalid && (!s_axil_b_rvalid || s_axil_b_rready || (PIPELINE_OUTPUT && !s_axil_b_rvalid_pipe_reg)) && (!s_axil_b_arready); if (write_eligible_b && (!read_eligible_b || last_read_b_reg)) begin last_read_b_next = 1'b0; s_axil_b_awready_next = 1'b1; s_axil_b_wready_next = 1'b1; s_axil_b_bresp_next = 2'b00; s_axil_b_bvalid_next = 1'b1; mem_wr_en_b = 1'b1; end else if (read_eligible_b) begin last_read_b_next = 1'b1; s_axil_b_arready_next = 1'b1; s_axil_b_rresp_next = 2'b00; s_axil_b_rvalid_next = 1'b1; mem_rd_en_b = 1'b1; end end always @(posedge b_clk) begin if (b_rst) begin last_read_b_reg <= 1'b0; s_axil_b_awready_reg <= 1'b0; s_axil_b_wready_reg <= 1'b0; s_axil_b_bvalid_reg <= 1'b0; s_axil_b_arready_reg <= 1'b0; s_axil_b_rresp_reg <= 2'b00; s_axil_b_rvalid_reg <= 1'b0; s_axil_b_rvalid_pipe_reg <= 1'b0; end else begin last_read_b_reg <= last_read_b_next; s_axil_b_awready_reg <= s_axil_b_awready_next; s_axil_b_wready_reg <= s_axil_b_wready_next; s_axil_b_bvalid_reg <= s_axil_b_bvalid_next; s_axil_b_arready_reg <= s_axil_b_arready_next; s_axil_b_rresp_reg <= s_axil_b_rresp_next; s_axil_b_rvalid_reg <= s_axil_b_rvalid_next; if (!s_axil_b_rvalid_pipe_reg || s_axil_b_rready) begin s_axil_b_rvalid_pipe_reg <= s_axil_b_rvalid_reg; end end s_axil_b_bresp_reg <= s_axil_b_bresp_next; if (mem_rd_en_b) begin s_axil_b_rdata_reg <= mem[s_axil_b_araddr_valid]; end else begin for (i = 0; i < WORD_WIDTH; i = i + 1) begin if (mem_wr_en_b && s_axil_b_wstrb[i]) begin mem[s_axil_b_awaddr_valid][8*i +: 8] <= s_axil_b_wdata[8*i +: 8]; end end end if (!s_axil_b_rvalid_pipe_reg || s_axil_b_rready) begin s_axil_b_rdata_pipe_reg <= s_axil_b_rdata_reg; s_axil_b_rresp_pipe_reg <= s_axil_b_rresp_reg; end end endmodule