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|
module memory_interface (
input clk,
input rstn,
input we,
input [31:0] addr,
input [31:0] wd,
output reg [31:0] rd
);
reg ram_we;
wire [31:0] ram_read_data, rom_read_data;
reg [31:0] rel_addr;
ram #(.N(32), .SIZE(1024)) ram(
.clk(clk),
.rstn(rstn),
.we(ram_we),
.addr(rel_addr),
.data_read(ram_read_data),
.data_write(wd)
);
rom #(.N(32), .SIZE(1024)) rom(
.clk(clk),
.addr(rel_addr),
.data_read(rom_read_data)
);
// 0000 0000 Reserved
// 0000 FFFF
//
// 0001 0000 ROM
// 000F FFFF
//
// 0010 0000 RAM
// FF0F FFFF
//
// FF10 0000 Reserved
// FFFF FFFF
always @(*) begin
if ( addr >= 32'h0001_0000 && addr <= 32'h000F_0000) begin
ram_we = 0;
rd = rom_read_data;
rel_addr = addr - 32'h0001_0000;
end else if (addr >= 32'h0010_0000 && addr <= 32'hFF0F_0000) begin
ram_we = we;
rd = ram_read_data;
rel_addr = addr - 32'h0010_0000;
end else begin
ram_we = 0;
rd = 0;
rel_addr = 0;
end
end
endmodule
|
