// Licensed to the Apache Software Foundation (ASF) under one // or more contributor license agreements. See the NOTICE file // distributed with this work for additional information // regarding copyright ownership. The ASF licenses this file // to you under the Apache License, Version 2.0 (the // "License"); you may not use this file except in compliance // with the License. You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, // software distributed under the License is distributed on an // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY // KIND, either express or implied. See the License for the // specific language governing permissions and limitations // under the License. // // Description: Clock divider to provide clock enables for // devices. // // Author.....: Alan Garfield // Niels A. Moseley // Date.......: 29-1-2018 // module pwr_reset( input clk14, // 14Mhz master clock input rst_n, // active low synchronous reset input enable, // clock enable output rst // active high synchronous system reset ); reg hard_reset; reg [5:0] reset_cnt; wire pwr_up_flag = &reset_cnt; always @(posedge clk14) begin if (rst_n == 1'b0) begin reset_cnt <= 6'b0; hard_reset <= 1'b0; end else if (enable) begin if (!pwr_up_flag) reset_cnt <= reset_cnt + 6'b1; hard_reset <= pwr_up_flag; end end assign rst = ~hard_reset; endmodule