| // ========== Copyright Header Begin ========================================== |
| // |
| // OpenSPARC T1 Processor File: ctu_mask_id.v |
| // Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved. |
| // DO NOT ALTER OR REMOVE COPYRIGHT NOTICES. |
| // |
| // The above named program is free software; you can redistribute it and/or |
| // modify it under the terms of the GNU General Public |
| // License version 2 as published by the Free Software Foundation. |
| // |
| // The above named 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 work; if not, write to the Free Software |
| // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. |
| // |
| // ========== Copyright Header End ============================================ |
| // |
| // Cluster Name: CTU |
| // Unit Name: ctu_mask_id |
| |
| // Mask programmable revision cell. The cell generates a 4-bit value based |
| // on the output of four 9-input XOR-trees. Each XOR-tree has an input |
| // connection to each of Niagara's 9 metal layers. The inputs are connected |
| // to 0 or 1 by means of metal straps connected to pull-downs and pull-ups. |
| // The cell is constructed such that only metal fill or removal is needed |
| // to alter the die's revision using any number of metal layer changes. |
| |
| module ctu_mask_id (/*AUTOARG*/ |
| // Outputs |
| mask_id |
| ); |
| |
| output [3:0] mask_id; |
| |
| parameter [9:1] id3_m = 9'b0; |
| parameter [9:1] id2_m = 9'b0; |
| parameter [9:1] id1_m = 9'b0; |
| parameter [9:1] id0_m = 9'b0; |
| |
| // Input layer : metal 1 metal 2 metal 3 metal 4 metal 5 metal 6 metal 7 metal 8 metal 9 |
| assign mask_id[0] = id0_m[1] ^ id0_m[2] ^ id0_m[3] ^ id0_m[4] ^ id0_m[5] ^ id0_m[6] ^ id0_m[7] ^ id0_m[8] ^ id0_m[9]; |
| assign mask_id[1] = id1_m[1] ^ id1_m[2] ^ id1_m[3] ^ id1_m[4] ^ id1_m[5] ^ id1_m[6] ^ id1_m[7] ^ id1_m[8] ^ id1_m[9]; |
| assign mask_id[2] = id2_m[1] ^ id2_m[2] ^ id2_m[3] ^ id2_m[4] ^ id2_m[5] ^ id2_m[6] ^ id2_m[7] ^ id2_m[8] ^ id2_m[9]; |
| assign mask_id[3] = id3_m[1] ^ id3_m[2] ^ id3_m[3] ^ id3_m[4] ^ id3_m[5] ^ id3_m[6] ^ id3_m[7] ^ id3_m[8] ^ id3_m[9]; |
| |
| endmodule |
