1 files changed, 84 insertions, 0 deletions
diff --git a/rtl/src/memory_interface.v b/rtl/src/memory_interface.v
new file mode 100644
index 0000000..09f05cb
--- /dev/null
+++ b/rtl/src/memory_interface.v
@@ -0,0 +1,84 @@
+module memory_interface (
+  input clk,
+  input rstn,
+
+  input we,
+  input [31:0] addr,
+  input [31:0] wd,
+
+  output reg [31:0] rd,
+
+  input [31:0] io_in,
+  output [31:0] io_out
+);
+
+`include "include/consts.vh"
+
+reg ram_we;
+reg io_we;
+wire [31:0] ram_rd, rom_rd;
+reg [31:0] rel_addr;
+
+ram #(.N(32), .SIZE(1024)) ram(
+  .clk(clk),
+  .rstn(rstn),
+  .we(ram_we),
+  .addr(rel_addr),
+  .data_read(ram_rd),
+  .data_write(wd)
+);
+
+rom #(.N(32), .SIZE(1024), .ROM_FILE("../../build/rom.hex")) rom(
+  .clk(clk),
+  .addr(rel_addr),
+  .data_read(rom_rd)
+);
+
+io io(
+  .clk(clk),
+  .rstn(rstn),
+  .we(io_we),
+  .addr(rel_addr),
+  .rd(io_rd),
+  .wd(wd),
+  .io_in(io_in),
+  .io_out(io_out)
+);
+
+
+// 0000 0000 Reserved
+// 0000 FFFF
+//
+// 0001 0000 ROM
+// 000F FFFF
+//
+// 0010 0000 RAM
+// FF0F FFFF
+//
+// FF10 0000 Reserved
+// FFFF FFFF
+
+
+always @ (*) begin
+  rd       = 0;
+  rel_addr = 0;
+  ram_we   = 0;
+  io_we    = 0;
+  if (         addr >= ROM_BEGIN && addr <= ROM_END) begin
+    rd = rom_rd;
+    rel_addr = addr - ROM_BEGIN;
+  end else if (addr >= RAM_BEGIN && addr <= RAM_END) begin
+    ram_we = we;
+    rd = ram_rd;
+    rel_addr = addr - RAM_BEGIN;
+  end else if (addr >= IO_BEGIN && addr <= IO_END) begin
+    io_we = we;
+    rd = io_rd;
+    rel_addr = addr - IO_BEGIN;
+  end else begin
+    rd = 0;
+    rel_addr = 0;
+  end
+end
+
+endmodule