initial commit

sim/sram.v

@@ -0,0 +1,52 @@
+`timescale 1ns/100ps
+module sram_sp #(
+    parameter AW = 16,
+    parameter Init_File = "none"
+)
+(
+    inout  [31:0] ram_data,  //BaseRAM数据，低8位与CPLD串口控制器共享
+    input [19:0] ram_addr, //BaseRAM地址
+    input [ 3:0] ram_be_n,  //BaseRAM字节使能，低有效。如果不使用字节使能，请保持为0
+    input  ram_ce_n,       //BaseRAM片选，低有效
+    input  ram_oe_n,       //BaseRAM读使能，低有效
+    input  ram_we_n        //BaseRAM写使能，低有效
+
+);
+    localparam AWT = ((1<<(AW-0))-1);
+
+    reg [31:0] BRAM [AWT:0];
+
+    initial begin
+        if(Init_File != "none") begin
+            $readmemb(Init_File,BRAM);
+        end
+    end
+    
+    reg     [AW-1:0]  addr_q1;
+    wire    [3:0]     write_enable;
+
+    assign write_enable[3:0] = (~ram_be_n) & {4{(~ram_ce_n) & (~ram_we_n)}};
+
+
+    always@(posedge write_enable[0]) begin
+		#10;
+        if(~ram_be_n[0]) BRAM[ram_addr][7:0] <= ram_data[7:0];
+    end
+    always@(posedge write_enable[1]) begin
+		#10;
+        if(~ram_be_n[1]) BRAM[ram_addr][15:8] <= ram_data[15:8];
+    end
+    always@(posedge write_enable[2]) begin
+		#10;
+        if(~ram_be_n[2]) BRAM[ram_addr][23:16] <= ram_data[23:16];
+    end
+    always@(posedge write_enable[3]) begin
+		#10;
+        if(~ram_be_n[3]) BRAM[ram_addr][31:24] <= ram_data[31:24];
+    end
+
+    wire [31:0] RDATA  = BRAM[ram_addr];
+
+    assign ram_data = ((~ram_ce_n) & (~ram_oe_n)) ?  RDATA  : 32'hzzzzzzzz;
+
+endmodule