module ram #(
  parameter DATA_W = 8,
  parameter ADDR_W = 8
)(
  input  logic              clk,
  input  logic              nreset,

  input  logic              cs_i,
  input  logic [ADDR_W-1:0] address_i,
  input  logic              we_i,
  input  logic [DATA_W-1:0] wdata_i,
  output logic [DATA_W-1:0] rdata_o
);

localparam RAM_SIZE = 2**ADDR_W;

logic [DATA_W-1:0] ram [RAM_SIZE-1:0];

logic [DATA_W-1:0] rdata;

logic              we;

assign we = cs_i & we_i;

always_ff @(posedge clk) begin
  if (we)
    ram[address_i] <= wdata_i;
end

always_ff @(posedge clk or negedge nreset) begin
  if (!nreset)
    rdata <= '0;
  else
    rdata <= ram[address_i];
end

assign rdata_o = {8{cs_i}} & rdata;

endmodule