Verilog 同步复位异步释放：电路设计技术详解及示例代码

Verilog\u662f\u4e00\u79cd\u786c\u4ef6\u63cf\u8ff0\u8bed\u8a00\uff0c\u7528\u4e8e\u63cf\u8ff0\u6570\u5b57\u7535\u8def\u3002\u5728 Verilog\u4e2d\uff0c\u540c\u6b65\u590d\u5236\u548c\u4e0d\u540c\u6b65\u9000\u653e\u662f\u4e2c\u79cd\u5e38\u89c1\u7684\u7535\u8def\u8bbe\u8ba1\u6280\u672f\u3002\n\n\u540c\u6b65\u590d\u5236\u6307\u7684\u662f\u4f7f\u7528\u65f6\u949f\u4fe1\u53f7\u6765\u540c\u6b65\u63a7\u5236\u590d\u5236\u64cd\u4f5c\u3002\u5f53\u65f6\u949f\u4fe1\u53f7\u4e3a\u9ad8\u7535\u5e73\u65f6\uff0c\u590d\u5236\u4fe1\u53f7\u6709\u6548\uff0c\u7535\u8def\u5904\u4e8e\u590d\u5236\u72b6\u6001\uff1b\u5f53\u65f6\u949f\u4fe1\u53f7\u4e3a\u4f4e\u7535\u5e73\u65f6\uff0c\u590d\u5236\u4fe1\u53f7\u65e0\u6548\uff0c\u7535\u8def\u4e0d\u5904\u4e8e\u590d\u5236\u72b6\u6001\u3002\u8fd9\u79cd\u8bbe\u8ba1\u65b9\u6cd5\u53ef\u4ee5\u786e\u4fdd\u590d\u5236\u64cd\u4f5c\u5728\u65f6\u949f\u7684\u4e0a\u5347\u754c\u6216\u4e0b\u964d\u754c\u65f6\u53d1\u751f\uff0c\u51cf\u5c11\u7531\u4e8e\u65f6\u5e8f\u95ee\u9898\u5f15\u8d77\u7684\u590d\u5236\u4fe1\u53f7\u7684\u632f\u52a8\u3002\n\n\u4e0d\u540c\u6b65\u9000\u653e\u6307\u7684\u662f\u5728\u7535\u8def\u4e2d\u4f7f\u7528\u4e0d\u540c\u6b65\u4fe1\u53f7\u6765\u9000\u653e\u590d\u5236\u72b6\u6001\u3002\u5f53\u4e0d\u540c\u6b65\u590d\u5236\u4fe1\u53f7\u4e3a\u9ad8\u7535\u5e73\u65f6\uff0c\u7535\u8def\u5904\u4e8e\u590d\u5236\u72b6\u6001\uff1b\u5f53\u4e0d\u540c\u6b65\u590d\u5236\u4fe1\u53f7\u4e3a\u4f4e\u7535\u5e73\u65f6\uff0c\u7535\u8def\u4e0d\u5904\u4e8e\u590d\u5236\u72b6\u6001\u3002\u4e0e\u540c\u6b65\u590d\u5236\u4e0d\u540c\u7684\u662f\uff0c\u4e0d\u540c\u6b65\u9000\u653e\u4fe1\u53f7\u53ef\u4ee5\u968f\u65f6\u53d1\u751f\uff0c\u4e0d\u9700\u8981\u4e0e\u65f6\u949f\u4fe1\u53f7\u540c\u6b65\u3002\u8fd9\u79cd\u8bbe\u8ba1\u65b9\u6cd5\u53ef\u4ee5\u5728\u590d\u5236\u4fe1\u53f7\u53d8\u6210\u4f4e\u7535\u5e73\u540e\u7acb\u5373\u9000\u653e\u7535\u8def\u590d\u5236\u72b6\u6001\uff0c\u63d0\u9ad8\u7535\u8def\u7684\u54cd\u5e94\u901f\u5ea6\u3002\n\n\u4ee5\u4e0b\u662f Verilog\u4e2d\u540c\u6b65\u590d\u5236\u548c\u4e0d\u540c\u6b65\u9000\u653e\u7684\u793a\u4f8b\u4ee3\u7801\uff1a\n\n\u540c\u6b65\u590d\u5236\uff1a\n\n```verilogmodule sync_reset ( input wire clk, input wire reset, //\u5176\u4ed6\u8f93\u5165\u8f93\u51fa\u7aef\u53e3);

reg [7:0] data;        always @(posedge clk) begin        if (reset) begin            //\u590d\u5236\u64cd\u4f5c            data <= 8'b0;        end else begin            //\u5176\u4ed6\u64cd\u4f5c            data <= data + 1;        end    end    endmodule\n\n\u4e0d\u540c\u6b65\u9000\u653e\uff1a\n\n```verilogmodule async_release (    input wire clk,    input wire async_reset,    //\u5176\u4ed6\u8f93\u5165\u8f93\u51fa\u7aef\u53e3);

reg [7:0] data;        always @(posedge clk or posedge async_reset) begin        if (async_reset) begin            //\u590d\u5236\u64cd\u4f5c            data <= 8'b0;        end else begin            //\u5176\u4ed6\u64cd\u4f5c            data <= data + 1;        end    end    endmodule\n\n\u5728\u540c\u6b65\u590d\u5236\u4e2d\uff0c\u590d\u5236\u4fe1\u53f7\u548c\u65f6\u949f\u4fe1\u53f7\u5728 always\u5757\u7684\u654f\u611f\u5217\u8868\u4e2d\u88ab\u6307\u5b9a\u4e3a posedge clk\u3002\u5728\u4e0d\u540c\u6b65\u9000\u653e\u4e2d\uff0c\u590d\u5236\u4fe1\u53f7\u548c\u65f6\u949f\u4fe1\u53f7\u90fd\u88ab\u6307\u5b9a\u4e3a posedge clk or posedge async_reset\uff0c\u8868\u793a\u590d\u5236\u4fe1\u53f7\u548c\u65f6\u949f\u4fe1\u53f7\u7684\u4e0a\u5347\u754c\u90fd\u53ef\u4ee5\u89e6\u52a8 always\u5757\u3002