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[/] [wb2axip/] [trunk/] [rtl/] [wbm2axisp.v] - Rev 13
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//////////////////////////////////////////////////////////////////////////////// // // Filename: wbm2axisp.v (Wishbone master to AXI slave, pipelined) // // Project: Pipelined Wishbone to AXI converter // // Purpose: The B4 Wishbone SPEC allows transactions at a speed as fast as // one per clock. The AXI bus allows transactions at a speed of // one read and one write transaction per clock. These capabilities work // by allowing requests to take place prior to responses, such that the // requests might go out at once per clock and take several clocks, and // the responses may start coming back several clocks later. In other // words, both protocols allow multiple transactions to be "in flight" at // the same time. Current wishbone to AXI converters, however, handle only // one transaction at a time: initiating the transaction, and then waiting // for the transaction to complete before initiating the next. // // The purpose of this core is to maintain the speed of both busses, while // transiting from the Wishbone (as master) to the AXI bus (as slave) and // back again. // // Since the AXI bus allows transactions to be reordered, whereas the // wishbone does not, this core can be configured to reorder return // transactions as well. // // Creator: Dan Gisselquist, Ph.D. // Gisselquist Technology, LLC // //////////////////////////////////////////////////////////////////////////////// // // Copyright (C) 2016, Gisselquist Technology, LLC // // This program is free software (firmware): you can redistribute it and/or // modify it under the terms of the GNU General Public License as published // by the Free Software Foundation, either version 3 of the License, or (at // your option) any later version. // // This program is distributed in the hope that it will be useful, but WITHOUT // ANY WARRANTY; without even the implied warranty of MERCHANTIBILITY or // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License // for more details. // // You should have received a copy of the GNU General Public License along // with this program. (It's in the $(ROOT)/doc directory, run make with no // target there if the PDF file isn't present.) If not, see // <http://www.gnu.org/licenses/> for a copy. // // License: GPL, v3, as defined and found on www.gnu.org, // http://www.gnu.org/licenses/gpl.html // // //////////////////////////////////////////////////////////////////////////////// // // `default_nettype none // module wbm2axisp #( parameter C_AXI_ID_WIDTH = 3, // The AXI id width used for R&W // This is an int between 1-16 parameter C_AXI_DATA_WIDTH = 128,// Width of the AXI R&W data parameter C_AXI_ADDR_WIDTH = 28, // AXI Address width (log wordsize) parameter DW = 32, // Wishbone data width parameter AW = 26, // Wishbone address width (log wordsize) parameter [0:0] STRICT_ORDER = 1 // Reorder, or not? 0 -> Reorder ) ( input wire i_clk, // System clock // input wire i_reset,// Wishbone reset signal--unused // AXI write address channel signals input wire i_axi_awready, // Slave is ready to accept output reg [C_AXI_ID_WIDTH-1:0] o_axi_awid, // Write ID output reg [C_AXI_ADDR_WIDTH-1:0] o_axi_awaddr, // Write address output wire [7:0] o_axi_awlen, // Write Burst Length output wire [2:0] o_axi_awsize, // Write Burst size output wire [1:0] o_axi_awburst, // Write Burst type output wire [0:0] o_axi_awlock, // Write lock type output wire [3:0] o_axi_awcache, // Write Cache type output wire [2:0] o_axi_awprot, // Write Protection type output wire [3:0] o_axi_awqos, // Write Quality of Svc output reg o_axi_awvalid, // Write address valid // AXI write data channel signals input wire i_axi_wready, // Write data ready output reg [C_AXI_DATA_WIDTH-1:0] o_axi_wdata, // Write data output reg [C_AXI_DATA_WIDTH/8-1:0] o_axi_wstrb, // Write strobes output wire o_axi_wlast, // Last write transaction output reg o_axi_wvalid, // Write valid // AXI write response channel signals input wire [C_AXI_ID_WIDTH-1:0] i_axi_bid, // Response ID input wire [1:0] i_axi_bresp, // Write response input wire i_axi_bvalid, // Write reponse valid output wire o_axi_bready, // Response ready // AXI read address channel signals input wire i_axi_arready, // Read address ready output wire [C_AXI_ID_WIDTH-1:0] o_axi_arid, // Read ID output wire [C_AXI_ADDR_WIDTH-1:0] o_axi_araddr, // Read address output wire [7:0] o_axi_arlen, // Read Burst Length output wire [2:0] o_axi_arsize, // Read Burst size output wire [1:0] o_axi_arburst, // Read Burst type output wire [0:0] o_axi_arlock, // Read lock type output wire [3:0] o_axi_arcache, // Read Cache type output wire [2:0] o_axi_arprot, // Read Protection type output wire [3:0] o_axi_arqos, // Read Protection type output reg o_axi_arvalid, // Read address valid // AXI read data channel signals input wire [C_AXI_ID_WIDTH-1:0] i_axi_rid, // Response ID input wire [1:0] i_axi_rresp, // Read response input wire i_axi_rvalid, // Read reponse valid input wire [C_AXI_DATA_WIDTH-1:0] i_axi_rdata, // Read data input wire i_axi_rlast, // Read last output wire o_axi_rready, // Read Response ready // We'll share the clock and the reset input wire i_wb_cyc, input wire i_wb_stb, input wire i_wb_we, input wire [(AW-1):0] i_wb_addr, input wire [(DW-1):0] i_wb_data, input wire [(DW/8-1):0] i_wb_sel, output reg o_wb_ack, output wire o_wb_stall, output reg [(DW-1):0] o_wb_data, output reg o_wb_err ); //***************************************************************************** // Parameter declarations //***************************************************************************** localparam LG_AXI_DW = ( C_AXI_DATA_WIDTH == 8) ? 3 : ((C_AXI_DATA_WIDTH == 16) ? 4 : ((C_AXI_DATA_WIDTH == 32) ? 5 : ((C_AXI_DATA_WIDTH == 64) ? 6 : ((C_AXI_DATA_WIDTH == 128) ? 7 : 8)))); localparam LG_WB_DW = ( DW == 8) ? 3 : ((DW == 16) ? 4 : ((DW == 32) ? 5 : ((DW == 64) ? 6 : ((DW == 128) ? 7 : 8)))); localparam LGFIFOLN = C_AXI_ID_WIDTH; localparam FIFOLN = (1<<LGFIFOLN); //***************************************************************************** // Internal register and wire declarations //***************************************************************************** // Things we're not changing ... assign o_axi_awlen = 8'h0; // Burst length is one assign o_axi_awsize = 3'b101; // maximum bytes per burst is 32 assign o_axi_awburst = 2'b01; // Incrementing address (ignored) assign o_axi_arburst = 2'b01; // Incrementing address (ignored) assign o_axi_awlock = 1'b0; // Normal signaling assign o_axi_arlock = 1'b0; // Normal signaling assign o_axi_awcache = 4'h2; // Normal: no cache, no buffer assign o_axi_arcache = 4'h2; // Normal: no cache, no buffer assign o_axi_awprot = 3'b010; // Unpriviledged, unsecure, data access assign o_axi_arprot = 3'b010; // Unpriviledged, unsecure, data access assign o_axi_awqos = 4'h0; // Lowest quality of service (unused) assign o_axi_arqos = 4'h0; // Lowest quality of service (unused) reg wb_mid_cycle, wb_mid_abort; wire wb_abort; // Command logic // Transaction ID logic wire [(LGFIFOLN-1):0] fifo_head; reg [(C_AXI_ID_WIDTH-1):0] transaction_id; initial transaction_id = 0; always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) transaction_id <= transaction_id + 1'b1; assign fifo_head = transaction_id; wire [(DW/8-1):0] no_sel; wire [(LG_AXI_DW-4):0] axi_bottom_addr; assign no_sel = 0; assign axi_bottom_addr = 0; // Write address logic initial o_axi_awvalid = 0; always @(posedge i_clk) o_axi_awvalid <= (!o_wb_stall)&&(i_wb_stb)&&(i_wb_we) ||(o_axi_awvalid)&&(!i_axi_awready); generate initial o_axi_awid = -1; always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) o_axi_awid <= transaction_id; if (C_AXI_DATA_WIDTH == DW) begin always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) // 26 bit address becomes 28 bit ... o_axi_awaddr <= { i_wb_addr[AW-1:0], axi_bottom_addr }; end else if (C_AXI_DATA_WIDTH / DW == 2) begin always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) // 26 bit address becomes 28 bit ... o_axi_awaddr <= { i_wb_addr[AW-1:1], axi_bottom_addr }; end else if (C_AXI_DATA_WIDTH / DW == 4) begin always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) // 26 bit address becomes 28 bit ... o_axi_awaddr <= { i_wb_addr[AW-1:2], axi_bottom_addr }; end endgenerate // Read address logic assign o_axi_arid = o_axi_awid; assign o_axi_araddr = o_axi_awaddr; assign o_axi_arlen = o_axi_awlen; assign o_axi_arsize = 3'b101; // maximum bytes per burst is 32 initial o_axi_arvalid = 1'b0; always @(posedge i_clk) o_axi_arvalid <= (!o_wb_stall)&&(i_wb_stb)&&(!i_wb_we) ||(o_axi_arvalid)&&(!i_axi_arready); // Write data logic generate if (C_AXI_DATA_WIDTH == DW) begin always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) o_axi_wdata <= i_wb_data; always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) o_axi_wstrb<= i_wb_sel; end else if (C_AXI_DATA_WIDTH/2 == DW) begin always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) o_axi_wdata <= { i_wb_data, i_wb_data }; always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) case(i_wb_addr[0]) 1'b0:o_axi_wstrb<={ no_sel,i_wb_sel }; 1'b1:o_axi_wstrb<={i_wb_sel, no_sel }; endcase end else if (C_AXI_DATA_WIDTH/4 == DW) begin always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) o_axi_wdata <= { i_wb_data, i_wb_data, i_wb_data, i_wb_data }; always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) case(i_wb_addr[1:0]) 2'b00:o_axi_wstrb<={ no_sel, no_sel, no_sel, i_wb_sel }; 2'b01:o_axi_wstrb<={ no_sel, no_sel, i_wb_sel, no_sel }; 2'b10:o_axi_wstrb<={ no_sel, i_wb_sel, no_sel, no_sel }; 2'b11:o_axi_wstrb<={ i_wb_sel, no_sel, no_sel, no_sel }; endcase end endgenerate assign o_axi_wlast = 1'b1; initial o_axi_wvalid = 0; always @(posedge i_clk) o_axi_wvalid <= ((!o_wb_stall)&&(i_wb_stb)&&(i_wb_we)) ||(o_axi_wvalid)&&(!i_axi_wready); // Read data channel / response logic assign o_axi_rready = 1'b1; assign o_axi_bready = 1'b1; wire [(LGFIFOLN-1):0] n_fifo_head, nn_fifo_head; assign n_fifo_head = fifo_head+1'b1; assign nn_fifo_head = { fifo_head[(LGFIFOLN-1):1]+1'b1, fifo_head[0] }; wire w_fifo_full; reg [(LGFIFOLN-1):0] fifo_tail; generate if (C_AXI_DATA_WIDTH == DW) begin if (STRICT_ORDER == 0) begin reg [(C_AXI_DATA_WIDTH-1):0] reorder_fifo_data [0:(FIFOLN-1)]; always @(posedge i_clk) if ((o_axi_rready)&&(i_axi_rvalid)) reorder_fifo_data[i_axi_rid] <= i_axi_rdata; always @(posedge i_clk) o_wb_data <= reorder_fifo_data[fifo_tail]; end else begin reg [(C_AXI_DATA_WIDTH-1):0] reorder_fifo_data; always @(posedge i_clk) reorder_fifo_data <= i_axi_rdata; always @(posedge i_clk) o_wb_data <= reorder_fifo_data; end end else if (C_AXI_DATA_WIDTH / DW == 2) begin reg reorder_fifo_addr [0:(FIFOLN-1)]; reg low_addr; always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) low_addr <= i_wb_addr[0]; always @(posedge i_clk) if ((o_axi_arvalid)&&(i_axi_arready)) reorder_fifo_addr[o_axi_arid] <= low_addr; if (STRICT_ORDER == 0) begin reg [(C_AXI_DATA_WIDTH-1):0] reorder_fifo_data [0:(FIFOLN-1)]; always @(posedge i_clk) if ((o_axi_rready)&&(i_axi_rvalid)) reorder_fifo_data[i_axi_rid] <= i_axi_rdata; always @(posedge i_clk) reorder_fifo_data[i_axi_rid] <= i_axi_rdata; always @(posedge i_clk) case(reorder_fifo_addr[fifo_tail]) 1'b0: o_wb_data <=reorder_fifo_data[fifo_tail][( DW-1): 0 ]; 1'b1: o_wb_data <=reorder_fifo_data[fifo_tail][(2*DW-1):( DW)]; endcase end else begin reg [(C_AXI_DATA_WIDTH-1):0] reorder_fifo_data; always @(posedge i_clk) reorder_fifo_data <= i_axi_rdata; always @(posedge i_clk) case(reorder_fifo_addr[fifo_tail]) 1'b0: o_wb_data <=reorder_fifo_data[( DW-1): 0 ]; 1'b1: o_wb_data <=reorder_fifo_data[(2*DW-1):( DW)]; endcase end end else if (C_AXI_DATA_WIDTH / DW == 4) begin reg [1:0] reorder_fifo_addr [0:(FIFOLN-1)]; reg [1:0] low_addr; always @(posedge i_clk) if ((i_wb_stb)&&(!o_wb_stall)) low_addr <= i_wb_addr[1:0]; always @(posedge i_clk) if ((o_axi_arvalid)&&(i_axi_arready)) reorder_fifo_addr[o_axi_arid] <= low_addr; if (STRICT_ORDER == 0) begin reg [(C_AXI_DATA_WIDTH-1):0] reorder_fifo_data [0:(FIFOLN-1)]; always @(posedge i_clk) if ((o_axi_rready)&&(i_axi_rvalid)) reorder_fifo_data[i_axi_rid] <= i_axi_rdata; always @(posedge i_clk) case(reorder_fifo_addr[fifo_tail][1:0]) 2'b00: o_wb_data <=reorder_fifo_data[fifo_tail][( DW-1): 0 ]; 2'b01: o_wb_data <=reorder_fifo_data[fifo_tail][(2*DW-1):( DW)]; 2'b10: o_wb_data <=reorder_fifo_data[fifo_tail][(3*DW-1):(2*DW)]; 2'b11: o_wb_data <=reorder_fifo_data[fifo_tail][(4*DW-1):(3*DW)]; endcase end else begin reg [(C_AXI_DATA_WIDTH-1):0] reorder_fifo_data; always @(posedge i_clk) reorder_fifo_data <= i_axi_rdata; always @(posedge i_clk) case(reorder_fifo_addr[fifo_tail][1:0]) 2'b00: o_wb_data <=reorder_fifo_data[( DW-1): 0]; 2'b01: o_wb_data <=reorder_fifo_data[(2*DW-1):( DW)]; 2'b10: o_wb_data <=reorder_fifo_data[(3*DW-1):(2*DW)]; 2'b11: o_wb_data <=reorder_fifo_data[(4*DW-1):(3*DW)]; endcase end end endgenerate // verilator lint_off UNUSED wire axi_rd_ack, axi_wr_ack, axi_ard_req, axi_awr_req, axi_wr_req, axi_rd_err, axi_wr_err; // verilator lint_on UNUSED // assign axi_ard_req = (o_axi_arvalid)&&(i_axi_arready); assign axi_awr_req = (o_axi_awvalid)&&(i_axi_awready); assign axi_wr_req = (o_axi_wvalid )&&(i_axi_wready); // assign axi_rd_ack = (i_axi_rvalid)&&(o_axi_rready); assign axi_wr_ack = (i_axi_bvalid)&&(o_axi_bready); assign axi_rd_err = (axi_rd_ack)&&(i_axi_rresp[1]); assign axi_wr_err = (axi_wr_ack)&&(i_axi_bresp[1]); // // We're going to need a FIFO on the return to make certain that we can // select the right bits from the return value, in the case where // DW != the axi data width. // // If we aren't using a strict order, this FIFO is can be used as a // reorder buffer as well, to place our out of order bus responses // back into order. Responses on the wishbone, however, are *always* // done in order. generate if (STRICT_ORDER == 0) begin // Reorder FIFO // // FIFO reorder buffer reg [(FIFOLN-1):0] reorder_fifo_valid; reg [(FIFOLN-1):0] reorder_fifo_err; initial reorder_fifo_valid = 0; initial reorder_fifo_err = 0; initial fifo_tail = 0; initial o_wb_ack = 0; initial o_wb_err = 0; always @(posedge i_clk) begin if (axi_rd_ack) begin reorder_fifo_valid[i_axi_rid] <= 1'b1; reorder_fifo_err[i_axi_rid] <= axi_rd_err; end if (axi_wr_ack) begin reorder_fifo_valid[i_axi_bid] <= 1'b1; reorder_fifo_err[i_axi_bid] <= axi_wr_err; end if (reorder_fifo_valid[fifo_tail]) begin o_wb_ack <= (!wb_abort)&&(!reorder_fifo_err[fifo_tail]); o_wb_err <= (!wb_abort)&&( reorder_fifo_err[fifo_tail]); fifo_tail <= fifo_tail + 1'b1; reorder_fifo_valid[fifo_tail] <= 1'b0; reorder_fifo_err[fifo_tail] <= 1'b0; end else begin o_wb_ack <= 1'b0; o_wb_err <= 1'b0; end if (!i_wb_cyc) begin // reorder_fifo_valid <= 0; // reorder_fifo_err <= 0; o_wb_err <= 1'b0; o_wb_ack <= 1'b0; end end reg r_fifo_full; initial r_fifo_full = 0; always @(posedge i_clk) begin if ((i_wb_stb)&&(!o_wb_stall) &&(reorder_fifo_valid[fifo_tail])) r_fifo_full <= (fifo_tail==n_fifo_head); else if ((i_wb_stb)&&(!o_wb_stall)) r_fifo_full <= (fifo_tail==nn_fifo_head); else if (reorder_fifo_valid[fifo_tail]) r_fifo_full <= 1'b0; else r_fifo_full <= (fifo_tail==n_fifo_head); end assign w_fifo_full = r_fifo_full; end else begin // // Strict ordering // reg reorder_fifo_valid; reg reorder_fifo_err; initial reorder_fifo_valid = 1'b0; initial reorder_fifo_err = 1'b0; always @(posedge i_clk) if (axi_rd_ack) begin reorder_fifo_valid <= 1'b1; reorder_fifo_err <= axi_rd_err; end else if (axi_wr_ack) begin reorder_fifo_valid <= 1'b1; reorder_fifo_err <= axi_wr_err; end else begin reorder_fifo_valid <= 1'b0; reorder_fifo_err <= 1'b0; end initial fifo_tail = 0; always @(posedge i_clk) if (reorder_fifo_valid) fifo_tail <= fifo_tail + 1'b1; initial o_wb_ack = 0; always @(posedge i_clk) o_wb_ack <= (reorder_fifo_valid)&&(i_wb_cyc)&&(!wb_abort); initial o_wb_err = 0; always @(posedge i_clk) o_wb_err <= (reorder_fifo_err)&&(i_wb_cyc)&&(!wb_abort); reg r_fifo_full; initial r_fifo_full = 0; always @(posedge i_clk) begin if ((i_wb_stb)&&(!o_wb_stall) &&(reorder_fifo_valid)) r_fifo_full <= (fifo_tail==n_fifo_head); else if ((i_wb_stb)&&(!o_wb_stall)) r_fifo_full <= (fifo_tail==nn_fifo_head); else if (reorder_fifo_valid) r_fifo_full <= 1'b0; else r_fifo_full <= (fifo_tail==n_fifo_head); end assign w_fifo_full = r_fifo_full; // verilator lint_off UNUSED wire [2*C_AXI_ID_WIDTH-1:0] strict_unused; assign strict_unused = { i_axi_bid, i_axi_rid }; // verilator lint_on UNUSED end endgenerate // // Wishbone abort logic // // Are we mid-cycle? initial wb_mid_cycle = 0; always @(posedge i_clk) if ((fifo_head != fifo_tail) ||(o_axi_arvalid)||(o_axi_awvalid) ||(o_axi_wvalid) ||(i_wb_cyc)&&(i_wb_stb)&&(!o_wb_stall)) wb_mid_cycle <= 1'b1; else wb_mid_cycle <= 1'b0; always @(posedge i_clk) if (wb_mid_cycle) wb_mid_abort <= (wb_mid_abort)||(!i_wb_cyc); else wb_mid_abort <= 1'b0; assign wb_abort = ((wb_mid_cycle)&&(!i_wb_cyc))||(wb_mid_abort); // Now, the difficult signal ... the stall signal // Let's build for a single cycle input ... and only stall if something // outgoing is valid and nothing is ready. assign o_wb_stall = (i_wb_cyc)&&( (w_fifo_full)||(wb_mid_abort) ||((o_axi_awvalid)&&(!i_axi_awready)) ||((o_axi_wvalid )&&(!i_axi_wready )) ||((o_axi_arvalid)&&(!i_axi_arready))); // Make Verilator happy // verilator lint_off UNUSED wire [2:0] unused; assign unused = { i_axi_bresp[0], i_axi_rresp[0], i_axi_rlast }; // verilator lint_on UNUSED ///////////////////////////////////////////////////////////////////////// // // // // Formal methods section // // These are only relevant when *proving* that this translator works // // // ///////////////////////////////////////////////////////////////////////// // // This section has been removed from this release. // endmodule
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