Files
ao486_MiSTer/rtl/common/simple_rom.v
2017-08-03 21:35:47 +08:00

60 lines
1.9 KiB
Verilog

/*
* Copyright (c) 2014, Aleksander Osman
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
module simple_rom
(
input clk,
input [widthad-1:0] addr_a,
output [width-1:0] q_a,
input [widthad-1:0] addr_b,
output [width-1:0] q_b
);
parameter width = 1;
parameter widthad = 1;
parameter datafile = "none";
reg [width-1:0] mem [(2**widthad)-1:0];
reg [widthad-1:0] rdaddr_a;
reg [widthad-1:0] rdaddr_b;
initial
begin
$readmemh(datafile, mem);
end
always @(posedge clk) begin
rdaddr_a <= addr_a;
rdaddr_b <= addr_b;
end
assign q_a = mem[rdaddr_a];
assign q_b = mem[rdaddr_b];
endmodule