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|
module memory_interface (
input clk,
input rstn,
input we,
input [31:0] addr,
output reg [31:0] rd,
input [31:0] wd
);
reg ram_we;
wire [31:0] ram_read_data, rom_read_data;
ram #(.N(32), .SIZE(1024)) ram(
.clk(clk),
.rst(!rstn),
.we(ram_we),
.addr(addr),
.data_read(ram_read_data),
.data_write(wd)
);
rom #(.N(32), .SIZE(1024)) rom(
.clk(clk),
.addr(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[31:16] >= 16'h0001 && addr[31:16] <= 16'h000F) begin
ram_we <= 0;
rd <= rom_read_data;
end else if (addr[31:16] >= 16'h0010 && addr[31:16] <= 16'hFF0F) begin
ram_we <= we;
rd <= ram_read_data;
end else if (addr[31:16] >= 16'hFF10 && addr[31:16] <= 16'hFFFF) begin
ram_we <= 0;
rd <= 0;
end else begin
ram_we <= 0;
rd <= 0;
end
end
endmodule
|
