Initial commit of OpenSPARC T2 design and verification files.

[OpenSPARC-T2-DV] / design / sys / iop / niu / rtl / niu_rdmc_rr_arbiter.v

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// OpenSPARC T2 Processor File: niu_rdmc_rr_arbiter.v
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/*************************************************************************
 *
 * File Name    : niu_rdmc_rr_arbiter.v
 * Author Name  : Jeanne Cai 
 * Description  :
 * Date Created : 10/29/2002
 *
 * Copyright (c) 2002, Sun Microsystems, Inc.
 * Sun Proprietary and Confidential
 *
 * Notes:
 *
 *************************************************************************/

module niu_rdmc_rr_arbiter (	req,
				token,
				gnt
				);

input[3:0]	req;
input[3:0]	token;
output[3:0]	gnt;

reg[3:0] gnt;

always @ (req or token)
begin
	if (token[0])
	begin
		gnt[0] = req[0];
		gnt[1] = !req[0] & req[1];
		gnt[2] = !req[0] & !req[1] & req[2];
		gnt[3] = !req[0] & !req[1] & !req[2] & req[3];
	end
	else if (token[1])
        begin
                gnt[1] = req[1];
                gnt[2] = !req[1] & req[2];
                gnt[3] = !req[1] & !req[2] & req[3];
                gnt[0] = !req[1] & !req[2] & !req[3] & req[0];
        end
	else if (token[2])
        begin
                gnt[2] = req[2];
                gnt[3] = !req[2] & req[3];
                gnt[0] = !req[2] & !req[3] & req[0];
                gnt[1] = !req[2] & !req[3] & !req[0] & req[1];
        end
	else if (token[3])
        begin
                gnt[3] = req[3];
                gnt[0] = !req[3] & req[0];
                gnt[1] = !req[3] & !req[0] & req[1];
                gnt[2] = !req[3] & !req[0] & !req[1] & req[2];
        end
	else
	begin
                gnt[0] = req[0];
                gnt[1] = !req[0] & req[1];
                gnt[2] = !req[0] & !req[1] & req[2];
                gnt[3] = !req[0] & !req[1] & !req[2] & req[3];
        end
end

endmodule