adding OPAE CSR support

2020-06-30 10:05:57 -07:00
parent 1f5c4bf617
commit 582a00d690
10 changed files with 334 additions and 94 deletions
--- a/hw/rtl/VX_csr_io_arb.v
+++ b/hw/rtl/VX_csr_io_arb.v
@@ -0,0 +1,85 @@
+`include "VX_define.vh"
+
+module VX_csr_io_arb #(
+    parameter NUM_REQUESTS = 1,
+    parameter REQS_BITS = `CLOG2(NUM_REQUESTS)
+) (
+    input wire clk,
+    input wire reset,
+
+    // input requests    
+    input wire                              in_csr_io_req_valid,
+    input wire [`NC_BITS-1:0]               in_csr_io_req_coreid,
+    input wire [11:0]                       in_csr_io_req_addr,
+    input wire                              in_csr_io_req_rw,
+    input wire [31:0]                       in_csr_io_req_data,
+    output wire                             in_csr_io_req_ready,
+
+    // input response
+    input wire [NUM_REQUESTS-1:0]           in_csr_io_rsp_valid,
+    input wire [NUM_REQUESTS-1:0][31:0]     in_csr_io_rsp_data,
+    output wire [NUM_REQUESTS-1:0]          in_csr_io_rsp_ready,
+
+    // output request
+    output wire [NUM_REQUESTS-1:0]          out_csr_io_req_valid,
+    output wire [NUM_REQUESTS-1:0][`NC_BITS-1:0] out_csr_io_req_coreid,
+    output wire [NUM_REQUESTS-1:0][11:0]    out_csr_io_req_addr,
+    output wire [NUM_REQUESTS-1:0]          out_csr_io_req_rw,
+    output wire [NUM_REQUESTS-1:0][31:0]    out_csr_io_req_data,
+    input wire [NUM_REQUESTS-1:0]           out_csr_io_req_ready,
+
+    // output response
+    output wire                             out_csr_io_rsp_valid,
+    output wire [31:0]                      out_csr_io_rsp_data,
+    input wire                              out_csr_io_rsp_ready
+);
+    if (NUM_REQUESTS == 1) begin
+
+        `UNUSED_VAR (clk)
+        `UNUSED_VAR (reset)
+
+        assign out_csr_io_req_valid  = in_csr_io_req_valid;
+        assign out_csr_io_req_coreid = in_csr_io_req_coreid;
+        assign out_csr_io_req_rw     = in_csr_io_req_rw;        
+        assign out_csr_io_req_addr   = in_csr_io_req_addr;
+        assign out_csr_io_req_data   = in_csr_io_req_data;
+        assign in_csr_io_req_ready   = out_csr_io_req_ready;
+
+        assign out_csr_io_rsp_valid  = in_csr_io_rsp_valid;
+        assign out_csr_io_rsp_data   = in_csr_io_rsp_data;
+        assign in_csr_io_rsp_ready   = out_csr_io_rsp_ready;
+
+    end else begin
+
+        reg [REQS_BITS-1:0] bus_rsp_sel;
+
+        VX_fixed_arbiter #(
+            .N(NUM_REQUESTS)
+        ) arbiter (
+            .clk         (clk),
+            .reset       (reset),
+            .requests    (in_csr_io_rsp_valid),
+            .grant_index (bus_rsp_sel),
+            `UNUSED_PIN  (grant_valid),
+            `UNUSED_PIN  (grant_onehot)
+        );
+
+        assign out_csr_io_rsp_valid = in_csr_io_rsp_valid [bus_rsp_sel];
+        assign out_csr_io_rsp_data  = in_csr_io_rsp_data [bus_rsp_sel];
+        assign in_csr_io_rsp_ready [bus_rsp_sel] = out_csr_io_rsp_ready;
+
+        genvar i;
+        
+        for (i = 0; i < NUM_REQUESTS; i++) begin                
+            assign out_csr_io_req_valid[i]  = in_csr_io_req_valid && in_csr_io_req_ready;
+            assign out_csr_io_req_coreid[i] = in_csr_io_req_coreid;
+            assign out_csr_io_req_rw[i]     = in_csr_io_req_rw;
+            assign out_csr_io_req_addr[i]   = in_csr_io_req_addr;
+            assign out_csr_io_req_data[i]   = in_csr_io_req_data;            
+        end
+
+        assign in_csr_io_req_ready = (& out_csr_io_req_ready);
+        
+    end
+
+endmodule