at_ctw5.v
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/**************************************************************************
* *
* Copyright (C) 1994, Silicon Graphics, Inc. *
* *
* These coded instructions, statements, and computer programs contain *
* unpublished proprietary information of Silicon Graphics, Inc., and *
* are protected by Federal copyright law. They may not be disclosed *
* to third parties or copied or duplicated in any form, in whole or *
* in part, without the prior written consent of Silicon Graphics, Inc. *
* *
*************************************************************************/
// $Id: at_ctw5.v,v 1.4 2003/01/15 03:34:09 berndt Exp $
////////////////////////////////////////////////////////////////////////
//
// Project Reality
//
// module: at_ctw5
// description: Counter for attribute buffers.
//
// designer: Phil Gossett
// date: 6/9/95
//
////////////////////////////////////////////////////////////////////////
module at_ctw5 (clk, rst, enb, z, a, b, c, d, e);
input clk;
input rst;
input enb;
output [2:0] z;
output a;
output b;
output c;
output d;
output e;
reg [2:0] z;
// counter
always @(posedge clk)
begin
if (rst == 1'b0)
z <= 3'b000; // 0
else
z <= enb ? {(z[1]&z[0]),(z[1]^z[0]),~(z[2]|z[0])} : z;
end
assign a = enb & (z == 3'b000);
assign b = enb & (z == 3'b001);
assign c = enb & (z == 3'b010);
assign d = enb & (z == 3'b011);
assign e = enb & (z == 3'b100);
endmodule // at_ctw5