// WARNING: Do NOT edit the input and output ports in this file in a text
// editor if you plan to continue editing the block that represents it in
// the Block Editor! File corruption is VERY likely to occur.
// Copyright (C) 1991-2009 Altera Corporation
// Your use of Altera Corporation's design tools, logic functions
// and other software and tools, and its AMPP partner logic
// functions, and any output files from any of the foregoing
// (including device programming or simulation files), and any
// associated documentation or information are expressly subject
// to the terms and conditions of the Altera Program License
// Subscription Agreement, Altera MegaCore Function License
// Agreement, or other applicable license agreement, including,
// without limitation, that your use is for the sole purpose of
// programming logic devices manufactured by Altera and sold by
// Altera or its authorized distributors. Please refer to the
// applicable agreement for further details.
// Generated by Quartus II Version 9.0 (Build Build 132 02/25/2009)
// Created on Thu Mar 19 21:45:05 2009
// Module Declaration
module CUD
(
// {{ALTERA_ARGS_BEGIN}} DO NOT REMOVE THIS LINE!
clk, BALE, SA, IOW, IOR, SBHE, PC, PD, PA, PB, IOCS16, SD
// {{ALTERA_ARGS_END}} DO NOT REMOVE THIS LINE!
);
// Port Declaration
// {{ALTERA_IO_BEGIN}} DO NOT REMOVE THIS LINE!
input clk;
input BALE;
input [15:0]SA;
input IOW;
input IOR;
input SBHE;
input [15:0]PC;
input [15:0]PD;
output [15:0]PA;
output [15:0]PB;
output IOCS16;
inout [15:0]SD;
reg [15:0]SDout,PA,PB;
reg IOCS16;
reg OE,holdIOR,holdIOW;
// {{ALTERA_IO_END}} DO NOT REMOVE THIS LINE!
assign SD = (OE)? SDout:16'bz;
always@(posedge clk)
begin
//control IOCS#16 =1
//if IOR ==1 && IOW ==1
begin
if(IOCS16 ==0)
begin
//hold IOR or IOW
if(IOR==0)
holdIOR = 1;
else if(IOW ==0)
holdIOW = 1;
//Read Over or Write Over
if(IOR & holdIOR || IOW & holdIOW)
begin
IOCS16 =1;
holdIOR =0;
holdIOW =0;
end
end
end
//check SA control IOCS#16
//SA = 0x0300 OR 0x03100 IOCS#16 = 0
begin
if (SA == 16'h0300)
IOCS16 = 0;
else if(SA == 16'h0310)
IOCS16 = 0;
end
//IOR = 0 when OE = 1 begin READ
begin
if(IOR == 0)
OE = 1;
else if(IOR == 1)
OE = 0;
end
//I/O read
//IOR# = 0 0 AND SA = 0x0300 OR 0x0310
//else SDout =0x0000
begin
if(IOR ==0 && SA == 16'h0300)
SDout = PC;
else if(IOR == 0 && SA == 16'h0310)
SDout = PD;
end
//I/O write
//IOW# = 0 AND SA = 0x0300 OR 0x0310
begin
if(IOW == 0 && SA == 16'h0300)
PA else if(IOW == 0 && SA == 16'h0310)
PB end
end
endmodule
