| 1 | // ========== Copyright Header Begin ========================================== |
| 2 | // |
| 3 | // OpenSPARC T2 Processor File: niu_smx_sm_req_datareq.v |
| 4 | // Copyright (C) 1995-2007 Sun Microsystems, Inc. All Rights Reserved |
| 5 | // 4150 Network Circle, Santa Clara, California 95054, U.S.A. |
| 6 | // |
| 7 | // * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 8 | // |
| 9 | // This program is free software; you can redistribute it and/or modify |
| 10 | // it under the terms of the GNU General Public License as published by |
| 11 | // the Free Software Foundation; version 2 of the License. |
| 12 | // |
| 13 | // This program is distributed in the hope that it will be useful, |
| 14 | // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | // GNU General Public License for more details. |
| 17 | // |
| 18 | // You should have received a copy of the GNU General Public License |
| 19 | // along with this program; if not, write to the Free Software |
| 20 | // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 21 | // |
| 22 | // For the avoidance of doubt, and except that if any non-GPL license |
| 23 | // choice is available it will apply instead, Sun elects to use only |
| 24 | // the General Public License version 2 (GPLv2) at this time for any |
| 25 | // software where a choice of GPL license versions is made |
| 26 | // available with the language indicating that GPLv2 or any later version |
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| 31 | // CA 95054 USA or visit www.sun.com if you need additional information or |
| 32 | // have any questions. |
| 33 | // |
| 34 | // ========== Copyright Header End ============================================ |
| 35 | |
| 36 | module niu_smx_sm_req_datareq( |
| 37 | /*AUTOARG*/ |
| 38 | // Outputs |
| 39 | rst_cmdflag, datareq_busy, datareq_idle, datareq, dreq_cs, |
| 40 | // Inputs |
| 41 | clk, reset_l, cmdflag, cmdflag_data, early_cmdflag_n, |
| 42 | early_cmdflag_data_n, dv_pad_done, cfg_pad_wait |
| 43 | ); |
| 44 | |
| 45 | input clk; |
| 46 | input reset_l; |
| 47 | |
| 48 | // cmdreq if |
| 49 | input cmdflag; |
| 50 | input [4:0] cmdflag_data; |
| 51 | input early_cmdflag_n; |
| 52 | input [4:0] early_cmdflag_data_n; |
| 53 | output rst_cmdflag; |
| 54 | output datareq_busy; |
| 55 | output datareq_idle; |
| 56 | |
| 57 | // dmc if |
| 58 | output datareq; |
| 59 | |
| 60 | // dv if |
| 61 | input dv_pad_done; |
| 62 | input cfg_pad_wait; |
| 63 | |
| 64 | output [2:0] dreq_cs; |
| 65 | |
| 66 | reg rst_cmdflag_n; |
| 67 | wire rst_cmdflag= rst_cmdflag_n; |
| 68 | |
| 69 | parameter s0= 3'h0, |
| 70 | s1= 3'h1, |
| 71 | s2= 3'h2, |
| 72 | s3= 3'h3, |
| 73 | s4= 3'h4, |
| 74 | s5= 3'h5; |
| 75 | |
| 76 | reg datareq_n, datareq; |
| 77 | reg [2:0] dreq_ns, dreq_cs; |
| 78 | wire datareq_busy= (!(dreq_cs==s0)|| cmdflag); |
| 79 | wire datareq_idle= (dreq_cs==s0); |
| 80 | |
| 81 | always @(posedge clk)begin |
| 82 | if(!reset_l) begin |
| 83 | datareq<= `SMX_PD 1'b0; |
| 84 | dreq_cs<= `SMX_PD s0; |
| 85 | end |
| 86 | else begin |
| 87 | datareq<= `SMX_PD datareq_n; |
| 88 | dreq_cs<= `SMX_PD dreq_ns; |
| 89 | end |
| 90 | end |
| 91 | |
| 92 | reg ld_cmdflag_data_n; |
| 93 | reg [4:0] cmdflag_data_r; |
| 94 | always @(posedge clk)begin |
| 95 | if(ld_cmdflag_data_n) cmdflag_data_r<= `SMX_PD (cmdflag)? cmdflag_data : |
| 96 | early_cmdflag_data_n; |
| 97 | end |
| 98 | |
| 99 | always @(/*AUTOSENSE*/cfg_pad_wait or cmdflag or cmdflag_data |
| 100 | or cmdflag_data_r or dreq_cs or dv_pad_done |
| 101 | or early_cmdflag_data_n or early_cmdflag_n) begin |
| 102 | datareq_n= 1'b0; |
| 103 | ld_cmdflag_data_n= 1'b0; |
| 104 | rst_cmdflag_n= 1'b0; |
| 105 | dreq_ns= dreq_cs; |
| 106 | case(dreq_cs) |
| 107 | s0: begin |
| 108 | if(cmdflag || early_cmdflag_n) begin // wait for flag |
| 109 | datareq_n= (cmdflag)? cmdflag_data[0] : early_cmdflag_data_n[0]; |
| 110 | ld_cmdflag_data_n= 1'b1; |
| 111 | rst_cmdflag_n= cmdflag; // clear flag for next |
| 112 | dreq_ns= s1; |
| 113 | end |
| 114 | end |
| 115 | s1: begin |
| 116 | datareq_n= cmdflag_data_r[1]; |
| 117 | dreq_ns= s2; |
| 118 | end |
| 119 | s2: begin |
| 120 | datareq_n= cmdflag_data_r[2]; |
| 121 | dreq_ns= s3; |
| 122 | end |
| 123 | s3: begin |
| 124 | datareq_n= cmdflag_data_r[3]; |
| 125 | dreq_ns= ((&cmdflag_data_r[3:0]) | ~cfg_pad_wait)? |
| 126 | ((cmdflag_data_r[4])? s5 : s0): s4; |
| 127 | end |
| 128 | s4: begin // wait dv done pad; |
| 129 | // only for pad case in case client |
| 130 | // pack lastline (which needs pad) |
| 131 | // with next line (no gap) |
| 132 | // (despite datareq issues gap at pad, |
| 133 | // no guarantee client return with same gap) |
| 134 | if(dv_pad_done) begin |
| 135 | dreq_ns= s0; |
| 136 | end |
| 137 | end |
| 138 | s5: begin // eop dummy state |
| 139 | dreq_ns= s0; |
| 140 | end |
| 141 | endcase |
| 142 | end |
| 143 | |
| 144 | endmodule |