fixed gpr_ram bug + io bus arbitration

hw/rtl/VX_mem_arb.v

@@ -0,0 +1,100 @@
+`include "VX_define.vh"
+
+module VX_mem_arb #(    
+    parameter NUM_REQUESTS  = 1, 
+    parameter WORD_SIZE     = 1, 
+    parameter TAG_IN_WIDTH  = 1,
+    parameter TAG_OUT_WIDTH = 1,
+
+    parameter WORD_WIDTH = WORD_SIZE * 8,
+    parameter ADDR_WIDTH = 32 - `CLOG2(WORD_SIZE),
+    parameter REQS_BITS  = `CLOG2(NUM_REQUESTS)
+) (
+    input wire clk,
+    input wire reset,
+
+    // input requests    
+    input wire [NUM_REQUESTS-1:0]                       in_mem_req_valid,
+    input wire [NUM_REQUESTS-1:0]                       in_mem_req_rw,  
+    input wire [NUM_REQUESTS-1:0][WORD_SIZE-1:0]        in_mem_req_byteen,  
+    input wire [NUM_REQUESTS-1:0][ADDR_WIDTH-1:0]       in_mem_req_addr,
+    input wire [NUM_REQUESTS-1:0][WORD_WIDTH-1:0]       in_mem_req_data,    
+    input wire [NUM_REQUESTS-1:0][TAG_IN_WIDTH-1:0]     in_mem_req_tag,    
+    output wire [NUM_REQUESTS-1:0]                      in_mem_req_ready,
+
+    // input response
+    output wire [NUM_REQUESTS-1:0]                      in_mem_rsp_valid,
+    output wire [NUM_REQUESTS-1:0][WORD_WIDTH-1:0]      in_mem_rsp_data,
+    output wire [NUM_REQUESTS-1:0][TAG_IN_WIDTH-1:0]    in_mem_rsp_tag,
+    input wire  [NUM_REQUESTS-1:0]                      in_mem_rsp_ready,
+
+    // output request
+    output wire                         out_mem_req_valid,
+    output wire                         out_mem_req_rw,  
+    output wire [WORD_SIZE-1:0]         out_mem_req_byteen,  
+    output wire [ADDR_WIDTH-1:0]        out_mem_req_addr,
+    output wire [WORD_WIDTH-1:0]        out_mem_req_data,    
+    output wire [TAG_OUT_WIDTH-1:0]     out_mem_req_tag,    
+    input wire                          out_mem_req_ready,
+
+    // output response
+    input wire                          out_mem_rsp_valid,
+    input wire [WORD_WIDTH-1:0]         out_mem_rsp_data,
+    input wire [TAG_OUT_WIDTH-1:0]      out_mem_rsp_tag,
+    output wire                         out_mem_rsp_ready
+);
+    if (NUM_REQUESTS == 1) begin
+
+        `UNUSED_VAR (clk)
+        `UNUSED_VAR (reset)
+
+        assign out_mem_req_valid  = in_mem_req_valid;
+        assign out_mem_req_rw     = in_mem_req_rw;
+        assign out_mem_req_byteen = in_mem_req_byteen;
+        assign out_mem_req_addr   = in_mem_req_addr;
+        assign out_mem_req_data   = in_mem_req_data;
+        assign out_mem_req_tag    = in_mem_req_tag;
+        assign in_mem_req_ready   = out_mem_req_ready;
+
+        assign in_mem_rsp_valid   = out_mem_rsp_valid;
+        assign in_mem_rsp_data    = out_mem_rsp_data;
+        assign in_mem_rsp_tag     = out_mem_rsp_tag;
+        assign out_mem_rsp_ready  = in_mem_rsp_ready;
+
+    end else begin
+
+        reg [REQS_BITS-1:0] bus_req_sel;
+
+        always @(posedge clk) begin
+            if (reset) begin      
+                bus_req_sel <= 0;
+            end else begin
+                bus_req_sel <= bus_req_sel + 1;
+            end
+        end
+
+        assign out_mem_req_valid  = in_mem_req_valid [bus_req_sel];
+        assign out_mem_req_rw     = in_mem_req_rw   [bus_req_sel];
+        assign out_mem_req_byteen = in_mem_req_byteen [bus_req_sel];
+        assign out_mem_req_addr   = in_mem_req_addr [bus_req_sel];
+        assign out_mem_req_data   = in_mem_req_data [bus_req_sel];
+        assign out_mem_req_tag    = {in_mem_req_tag [bus_req_sel], REQS_BITS'(bus_req_sel)};
+
+        genvar i;
+
+        for (i = 0; i < NUM_REQUESTS; i++) begin
+            assign in_mem_req_ready[i] = out_mem_req_ready && (bus_req_sel == REQS_BITS'(i));
+        end
+
+        wire [REQS_BITS-1:0] bus_rsp_sel = out_mem_rsp_tag[REQS_BITS-1:0];
+        
+        for (i = 0; i < NUM_REQUESTS; i++) begin                
+            assign in_mem_rsp_valid[i] = out_mem_rsp_valid && (bus_rsp_sel == REQS_BITS'(i));
+            assign in_mem_rsp_data[i]  = out_mem_rsp_data;
+            assign in_mem_rsp_tag[i]   = out_mem_rsp_tag[REQS_BITS +: TAG_IN_WIDTH];              
+        end
+        assign out_mem_rsp_ready = in_mem_rsp_ready[bus_rsp_sel];
+
+    end
+
+endmodule