9086/system/memory.v

38 lines
1.2 KiB
Verilog

/* memory.v - implementation of memory external to the 9086 CPU for testing purposes
This file is part of the 9086 project.
Copyright (c) 2023 Efthymios Kritikos
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>. */
module mem(input [19:0] address,inout wire [15:0] data ,input rd,input wr,input cs);
reg [15:0] memory [0:8191];
initial begin
string boot_code;
if(!$value$plusargs("BOOT_CODE=%s",boot_code))begin
$display("No boot code specified. Please add +BOOT_CODE=<path> to your vvp args");
$finish;
end
$readmemh(boot_code, memory);
end
assign data = !rd & !cs ? memory[address]: 'hz;
always @(negedge wr) begin
memory[address]=data;
end
endmodule