{"id":734,"date":"2024-11-20T14:48:55","date_gmt":"2024-11-20T06:48:55","guid":{"rendered":"https:\/\/zhewana.cn\/?p=734"},"modified":"2024-11-20T14:50:03","modified_gmt":"2024-11-20T06:50:03","slug":"ug949-xilinx%e5%b9%b3%e5%8f%b0%e7%a1%ac%e4%bb%b6%e8%ae%be%e8%ae%a1%e6%96%b9%e6%b3%95%e6%8c%87%e5%8d%97-%e6%8e%a7%e5%88%b6%e4%bf%a1%e5%8f%b7%e5%92%8c%e6%8e%a7%e5%88%b6%e9%9b%86%e7%af%87","status":"publish","type":"post","link":"https:\/\/zhewana.cn\/?p=734","title":{"rendered":"ug949-Xilinx\u5e73\u53f0\u786c\u4ef6\u8bbe\u8ba1\u65b9\u6cd5\u6307\u5357-\u63a7\u5236\u4fe1\u53f7\u548c\u63a7\u5236\u96c6\u7bc7"},"content":{"rendered":"<p>\u4f5c\u4e3a\u4e00\u4e2a\u4ece\u5d4c\u8f6f\u8dd1\u6765\u5b66 FPGA \u7684\u83dc\u9e1f\uff0c\u7b14\u8005\u6bcf\u6b21\u52a8\u624b\u5199 verilog \u4ee3\u7801\u7684\u65f6\u5019\u90fd\u6709\u4e00\u79cd\u5f88\u62e7\u5df4\u7684\u611f\u89c9\uff0c\u603b\u89c9\u7684\u81ea\u5df1\u4f3c\u4e4e\u8fd8\u662f\u6709\u4e9b\u5730\u65b9\u7684\u7406\u89e3\u6709\u95ee\u9898\u3002<br \/>\n\u7f51\u4e0a\u770b\u4e86\u65e0\u6570\u7bc7\u8bb2\u786c\u4ef6\u601d\u7ef4\u7684\u6587\u7ae0\uff0c\u5927\u5bb6\u65e0\u4e00\u4f8b\u5916\u90fd\u662f\u544a\u8bc9\u4f60\u5199 verilog \u4ee3\u7801\u7684\u65f6\u5019\u6700\u91cd\u8981\u7684\u5c31\u662f\u8981\u5fc3\u4e2d\u6709\u7535\u8def\uff0c\u4f46\u662f\u600e\u4e48\u624d\u80fd\u5fc3\u4e2d\u6709\u7535\u8def\u5462\uff1f\u6570\u5b57\u7535\u8def\u7684\u8bbe\u8ba1\u548c\u8f6f\u4ef6\u7cfb\u7edf\u8bbe\u8ba1\u7684\u601d\u7ef4\u7a76\u7adf\u6709\u4ec0\u4e48\u4e0d\u540c\uff1f<br \/>\n\u4e8e\u662f\u6000\u7740\u8fd9\u4efd\u7591\u95ee\u7b14\u8005\u6253\u5f00\u4e86 Xilinx \u7684\u8fd9\u7bc7\u5b98\u65b9\u6587\u6863\uff1a<strong>UltraFast Design Methodology Guide for Xilinx FPGAs and SoCs<\/strong>\uff0c\u5e0c\u671b\u80fd\u4ece\u4e2d\u627e\u5230\u7b54\u6848\u5427\u3002<\/p>\n<blockquote>\n<p>\u53e0\u7532\uff1a\u4ee5\u4e0b\u5185\u5bb9\u5747\u6765\u81eaXilinx \u5b98\u65b9\u6587\u6863 ug949 \u4ee5\u53ca\u7b14\u8005\u81ea\u5df1\u5bf9\u6587\u6863\u5185\u5bb9\u7684\u7406\u89e3\u3002<br \/>\n\u5982\u6709\u9519\u8bef\uff0c\u8fd8\u671b\u65a7\u6b63\u3002<\/p>\n<\/blockquote>\n<p>\u672c\u6587\u53c2\u8003\u81ea <code>ug949-Ch .3 \u4f7f\u7528 RTL \u8fdb\u884c\u8bbe\u8ba1<\/code> \u4e2d\u7684 <code>RTL \u7f16\u7801\u6307\u5bfc<\/code> \u5c0f\u8282\uff0c\u672c\u7bc7\u4e3a\u5176\u4e2d\u7684\u63a7\u5236\u4fe1\u53f7\u4e0e\u63a7\u5236\u96c6\u5c0f\u8282\uff0c\u5927\u81f4\u63a2\u8ba8\u4e86 RTL \u8bbe\u8ba1\u4e2d\u7684<strong>\u590d\u4f4d<\/strong>\u3001<strong>\u65f6\u949f\u4f7f\u80fd<\/strong>\u548c<strong>\u63a7\u5236\u4f7f\u80fd<\/strong>\u8fd9\u51e0\u4e2a\u63a7\u5236\u4fe1\u53f7\u5728\u7efc\u5408\u65f6\u7684\u884c\u4e3a\u548c\u7f16\u7801\u5efa\u8bae\u3002<\/p>\n<h2>\u5173\u4e8e\u590d\u4f4d\u4fe1\u53f7<\/h2>\n<p>\u6570\u5b57\u7535\u8def\u8bbe\u8ba1\u4e2d\uff0c\u590d\u4f4d\u7684\u91cd\u8981\u6027\u4e0d\u8a00\u800c\u55bb\u3002\u800c\u5728 FPGA \u8bbe\u8ba1\u4e2d\uff0c\u4e0d\u5f53\u7684\u590d\u4f4d\u8bbe\u8ba1\u53ef\u80fd\u4f1a\u5bfc\u81f4\u7efc\u5408\u5668\u63a8\u65ad\u51fa\u4e0d\u5408\u9002\u7684\u5668\u4ef6\u3002\u867d\u7136\u5728\u529f\u80fd\u4e0a\u53ef\u80fd\u6ca1\u6709\u95ee\u9898\uff0c\u4f46\u662f\u5bf9\u4e8e\u9762\u79ef\u548c\u786c\u4ef6\u8d44\u6e90\u90fd\u662f\u4e00\u79cd\u6d6a\u8d39\u3002<\/p>\n<h3>\u4e0d\u5f53\u590d\u4f4d\u6709\u5565\u95ee\u9898\uff1f<\/h3>\n<p>\u540c\u6b65\u7535\u8def\u4ee3\u7801\u53ef\u80fd\u63a8\u65ad\u51fa\u4e00\u4e0b\u51e0\u79cd\u5668\u4ef6\uff1a<\/p>\n<ul>\n<li>\u67e5\u627e\u8868<\/li>\n<li>\u5bc4\u5b58\u5668<\/li>\n<li>\u79fb\u4f4d\u5bc4\u5b58\u5668<\/li>\n<li>BlockRAM \u6216\u8005 LUT RAM<\/li>\n<li>DSP48 \u5bc4\u5b58\u5668<br \/>\n\u7531\u4e8e\u4e0d\u540c\u5668\u4ef6\u7684\u590d\u4f4d\u65b9\u5f0f\u4e0d\u540c\uff0c\u6240\u4ee5\u4f1a\u5bfc\u81f4\u4f7f\u7528\u4e0d\u540c\u7684\u590d\u4f4d\u65b9\u5f0f\u65f6\u7efc\u5408\u51fa\u4e0d\u540c\u7684\u5668\u4ef6\u3002\u624b\u518c\u4e2d\u4e3a\u6211\u4eec\u4e3e\u4e86\u4e2a\u5178\u578b\u7684\u4f8b\u5b50\uff1a<strong>\u5728\u4e58\u6cd5\u5668\u7684\u8f93\u5165\u6216\u8f93\u51fa\u5904\u63cf\u8ff0\u7684\u5f02\u6b65\u590d\u4f4d\u4f1a\u5bfc\u81f4\u5bc4\u5b58\u5668\u88ab\u7efc\u5408\u5230 Slice \u4e2d\u800c\u4e0d\u662f DSP \u5757\u4e2d\u3002<\/strong><\/li>\n<\/ul>\n<h3>\u4ec0\u4e48\u65f6\u5019\u5e94\u8be5\u590d\u4f4d\uff1f<\/h3>\n<p>\u9274\u4e8e Xilinx \u5668\u4ef6\u4e2d\u6709 GSR\uff08\u5168\u5c40\u7f6e\u590d\u4f4d\u4fe1\u53f7\uff09\u7684\u5b58\u5728\uff0c\u5728\u7247\u5b50\u542f\u52a8\u540e\uff0c\u5185\u90e8\u6240\u6709\u5668\u4ef6\u7684\u521d\u59cb\u72b6\u6001\u5176\u5b9e\u90fd\u662f\u5df2\u77e5\u7684\u3002<strong>\u56e0\u6b64\u6ca1\u6709\u5fc5\u8981\u5355\u7eaf\u4e3a\u4e86\u4e0a\u7535\u65f6\u521d\u59cb\u5316\u8bbe\u5907\u800c\u7f16\u5199\u590d\u4f4d\u4ee3\u7801\u3002<\/strong><br \/>\n\u5173\u4e8e\u5e94\u8be5\u5982\u4f55\u8fdb\u884c\u590d\u4f4d\u8bbe\u8ba1\uff0c\u624b\u518c\u4e2d\u662f\u8fd9\u4e48\u8bf4\u7684\uff1a<\/p>\n<blockquote>\n<p>Xilinx highly recommends that you take special care in deciding when the design requires a reset, and when it does not. In many situations, resets might be required on the control path logic for proper operation. However, resets are generally less necessary on the data path logic.<\/p>\n<\/blockquote>\n<p>\u5373\uff1a\u5f88\u591a\u65f6\u5019\uff0c<strong>\u5bf9\u63a7\u5236\u8def\u5f84\u7684\u590d\u4f4d\u662f\u5fc5\u8981\u7684\uff0c\u800c\u5bf9\u6570\u636e\u8def\u5f84\u7684\u590d\u4f4d\u662f\u4e0d\u5fc5\u8981\u7684<\/strong>\u3002<\/p>\n<blockquote>\n<p>Evaluate each synchronous block, and attempt to determine whether a reset is required for proper operation. <strong>Do not code the reset by default without ascertaining its real need.<\/strong><\/p>\n<\/blockquote>\n<p>\u5728\u8bc4\u4f30\u6bcf\u4e00\u4e2a\u540c\u6b65\u5757\u4ee5\u540e\u5728\u51b3\u5b9a\u662f\u5426\u8981\u4e3a\u5176\u6dfb\u52a0\u590d\u4f4d\u529f\u80fd\uff0c\u4e0d\u8981\u8d77\u624b\u5c31\u662f\u4e00\u4e2a\u590d\u4f4d\u540c\u6b65\u5757\u6a21\u677f\u8d34\u4e0a\u53bb\u3002\u4e3a\u4e86\u4fbf\u4e8e\u8bc4\u4f30\u6bcf\u4e2a\u6a21\u5757\u662f\u5426\u786e\u5b9e\u9700\u8981\u590d\u4f4d\u529f\u80fd\uff0c\u53ef\u4ee5\u4f7f\u7528\u529f\u80fd\u4eff\u771f\u6765\u8fdb\u884c\u786e\u8ba4\u3002<br \/>\n\uff08PS\uff1a\u7b14\u8005\u81ea\u5df1\u5c31\u5f88\u559c\u6b22\u8d34\u590d\u4f4d\u540c\u6b65\u5757\u6a21\u677f\ud83d\ude2d\uff09<\/p>\n<h3>\u540c\u6b65\u590d\u4f4d or \u5f02\u6b65\u590d\u4f4d\uff1f<\/h3>\n<p>\u9996\u5148\uff0cXilinx \u5b98\u65b9\u63a8\u8350\u6211\u4eec\u4f7f\u7528<strong>\u540c\u6b65\u590d\u4f4d\u65b9\u5f0f<\/strong>\u3002<br \/>\n\u5bf9\u4e8e\u5927\u90e8\u5206\u5382\u5546\u800c\u8a00\uff0c\u7247\u5b50\u4e2d\u7684\u5668\u4ef6\u662f\u5177\u6709\u5f02\u6b65\u590d\u4f4d\u7684\u63a5\u53e3\u800c\u4e0d\u5177\u6709\u540c\u6b65\u590d\u4f4d\u7684\u63a5\u53e3\u7684\uff0c\u6240\u4ee5\u5f02\u6b65\u590d\u4f4d\u76f8\u5bf9\u4e8e\u540c\u6b65\u590d\u4f4d\u800c\u8a00\u5176\u5b9e\u662f\u66f4\u52a0\u8282\u7701\u8d44\u6e90\u7684\uff0c\u8fd9\u662f\u5f02\u6b65\u590d\u4f4d\u7684\u4f18\u70b9\u3002<br \/>\n\u4e0d\u8fc7\u5f02\u6b65\u590d\u4f4d\u7684\u7f3a\u70b9\u66f4\u662f\u4e00\u5806\uff1a\u4e0d\u4ec5\u4e0d\u65b9\u4fbf\u5e03\u7ebf\uff0c\u8fd8\u53ef\u80fd\u7834\u574f RAM \u548c\u79fb\u4f4d\u5bc4\u5b58\u5668\u4e2d\u5b58\u50a8\u7684\u5185\u5bb9\u3002\u53e6\u5916\u5bf9\u4e8e DSP 48 \u548c BRAM \u8fd9\u79cd\u53ea\u6709\u540c\u6b65\u590d\u4f4d\u63a5\u53e3\u7684\u5668\u4ef6\u800c\u8a00\uff0c\u4f7f\u7528\u5f02\u6b65\u590d\u4f4d\u751a\u81f3\u4f1a\u5bfc\u81f4\u7efc\u5408\u5668\u4e0d\u4f7f\u7528 DSP \u548c BRAM \u4e2d\u7684\u5668\u4ef6\u6765\u5b9e\u73b0\u4f60\u6240\u5199\u7684\u529f\u80fd\uff0c\u5373\u524d\u6587\u6240\u63d0\u5230\u7684\u4e0d\u5f53\u7684\u590d\u4f4d\u65b9\u5f0f\u4f1a\u5bfc\u81f4\u7684\u95ee\u9898\u4e4b\u4e00\u3002<br \/>\n\u867d\u8bf4\u540c\u6b65\u590d\u4f4d\u633a\u597d\uff0c\u4e0d\u8fc7\u540c\u6b65\u590d\u4f4d\u9700\u8981\u590d\u4f4d\u4fe1\u53f7\u7684\u5bbd\u5ea6\u81f3\u5c11\u8981\u8fbe\u5230\u4e00\u4e2a\u65f6\u949f\u5468\u671f\u624d\u80fd\u6210\u529f\u590d\u4f4d\u7684\u8fd9\u70b9\u4e5f\u5f88\u607c\u4eba\u3002<br \/>\n<a href=\"https:\/\/blog.csdn.net\/zhoutaopower\/article\/details\/102831660\">Verilog HDL \u540c\u6b65\u590d\u4f4d\u548c\u5f02\u6b65\u590d\u4f4d<\/a>\u8fd9\u7bc7\u6587\u7ae0\u4e2d\u5bf9\u590d\u4f4d\u4fe1\u53f7\u8fdb\u884c\u4e86\u8be6\u7ec6\u7684\u63a2\u8ba8\uff0c\u5176\u4e2d\u63d0\u5230\u4e86\u590d\u4f4d\u63a8\u8350\u4f7f\u7528\u7684\u5f02\u6b65\u590d\u4f4d\u540c\u6b65\u91ca\u653e\u7684\u65b9\u6cd5\u5176\u5b9e\u5728\u624b\u518c\u4e2d\u4e5f\u6709\u63d0\u5230\uff1a<\/p>\n<blockquote>\n<p>When using asynchronous resets, remember to synchronize the deassertion of the asynchronous reset. Although the relative timing between clock and reset can be ignored during reset assertion, the reset release must be synchronized to the clock.<\/p>\n<\/blockquote>\n<h3>\u91cd\u6784\u590d\u4f4d\u4ee3\u7801\u65f6\u7684\u95ee\u9898<\/h3>\n<p>\ud83d\udc4c\uff0c\u73b0\u5728\u6211\u5df2\u7ecf\u5b8c\u5168\u638c\u63e1\u590d\u4f4d\u4e86\ud83d\udcaa\uff0c\u5e76\u4e14\u6253\u7b97\u91cd\u6784\u81ea\u5df1\u7684\u590d\u4f4d\u4ee3\u7801\u6253\u7b97\u5927\u5c55\u62f3\u811a\uff01<\/p>\n<p>\u4e8e\u662f\u6211\u628a\u81ea\u5df1\u4ee3\u7801\u4e2d\u4e0d\u9700\u8981\u590d\u4f4d\u7684\u5730\u65b9\u6ce8\u91ca\u6389\u4e86\uff1a<\/p>\n<pre><code class=\"language-verilog\">always @(posedge clk or posedge rst) begin\n    if (rst) begin\n        \/\/din dly1 &lt;= 16'b0;\n        \/\/din_dly2 &lt;= 16'b0;\n        dout = 16'b0;\n    end else begin\n        din_dly1 &lt;= din;\n        din_dly2 &lt;= din_dly1;\n        dout &lt;= din_dly2;\n    end\nend\n<\/code><\/pre>\n<p>\u7136\u800c\u8fd9\u6837\u4fee\u6539\u7684\u7ed3\u679c\u662f\uff1a<code>din_dly2<\/code> \u548c <code>din_dly1<\/code> \u7684\u4fe1\u53f7\u4ecd\u7136\u4f1a\u88ab\u5f02\u6b65\u590d\u4f4d\u3002<br \/>\n\u663e\u7136\u8fd9\u4e24\u4e2a\u4fe1\u53f7\u4ecd\u7136\u5904\u5728\u5f02\u6b65\u590d\u4f4d\u7684\u903b\u8f91\u5f53\u4e2d\uff0c\u800c\u590d\u4f4d\u7684 if \u91cc\u9762\u6ca1\u6709\u4e3a\u8fd9\u4e24\u4e2a\u4fe1\u53f7\u8d4b\u503c\u770b\u8d77\u6765\u5176\u5b9e\u66f4\u50cf\u662f\u4f60\u5fd8\u8bb0\u628a\u4ed6\u4eec\u5199\u8fdb\u53bb\u4e86\uff0c\u800c\u4e0d\u662f\u4f60\u4e0d\u60f3\u5bf9\u8fd9\u4e24\u4e2a\u4fe1\u53f7\u8fdb\u884c\u590d\u4f4d\uff0c\u8fd9\u65f6&quot;\u806a\u660e\u7684&quot;\u7efc\u5408\u5668\u5c31\u4f1a\u4e00\u8138\u65e0\u5948\u7684\u5e2e\u4f60\u628a\u4f60\u5fd8\u8bb0\u6dfb\u52a0\u7684\u4e1c\u897f\u8865\u4e0a\u53bb\u3002<\/p>\n<p>\u8981\u60f3\u7efc\u5408\u5668\u80fd\u591f\u6b63\u786e\u7684\u4e86\u89e3\u5230\u4f60\u7684\u610f\u56fe\uff0c\u5c31\u5fc5\u987b\u6452\u5f03\u4e0a\u9762\u8fd9\u79cd\u201c\u66a7\u6627\u201d\u7684\u4ee3\u7801\uff0c\u8f6c\u800c\u4f7f\u7528\u66f4\u52a0\u6e05\u6670\u7684\u8868\u8ff0\uff1a<\/p>\n<pre><code class=\"language-verilog\">always @(posedge clk) begin\n    din_dly1 &lt;= din;\n    din_dly2 &lt;= din_dly1;\nend\n\nalways @(posedge clk or posedge rst) begin\n    if (rst) dout &lt;= 16'd0;\n    else dout &lt;= din_dly2;\nend\n<\/code><\/pre>\n<p>\u53e6\uff1a\u5f53\u4f7f\u7528\u590d\u4f4d\u65f6\uff0c\u4e00\u5b9a\u8981\u786e\u4fdd\u8bbe\u8ba1\u4e2d\u7684\u6240\u6709\u5bc4\u5b58\u5668\u90fd\u88ab\u590d\u4f4d\u3002<\/p>\n<h2>\u5173\u4e8e\u65f6\u949f\u4f7f\u80fd\u4fe1\u53f7<\/h2>\n<p>\u5982\u679c\u4f60\u548c\u7b14\u8005\u4e00\u6837\u505a\u8fc7\u5355\u7247\u673a\u7684\u8bdd\uff0c\u5e94\u8be5\u5bf9\u4f4e\u529f\u8017\u8bbe\u8ba1\u6709\u6240\u8033\u95fb\u3002\u5728\u4f4e\u529f\u8017\u8bbe\u8ba1\u4e2d\uff0c\u964d\u4f4e\u529f\u8017\u4e14\u4e0d\u5f71\u54cd\u5176\u4ed6\u529f\u80fd\u6700\u6709\u6548\u7684\u65b9\u6cd5\u5c31\u662f\u964d\u4f4e\u65f6\u949f\u9891\u7387\uff0c\u800c\u5728\u4f4e\u529f\u8017\u578b\u53f7\u7684\u5355\u7247\u673a\u4e2d\uff0c\u66f4\u662f\u62e5\u6709\u76f4\u63a5\u5c06\u65f6\u949f\u6682\u65f6\u5173\u95ed\u7684\u6df1\u5ea6\u7761\u7720\u6a21\u5f0f\u3002\u5728 FPGA \u4e2d\u65f6\u949f\u81ea\u7136\u4e5f\u662f\u5f71\u54cd\u4e00\u4e2a\u7cfb\u7edf\u529f\u8017\u7684\u91cd\u8981\u56e0\u7d20\uff0c\u56e0\u6b64\u901a\u8fc7\u5173\u95ed\u65f6\u949f\u4f7f\u80fd\u53ef\u4ee5\u505a\u5230\u5728\u4e0d\u5f71\u54cd\u7cfb\u7edf\u529f\u80fd\u7684\u60c5\u51b5\u4e0b\u663e\u8457\u964d\u4f4e\u7cfb\u7edf\u529f\u8017\u3002\u7136\u800c\uff0c\u5982\u679c\u4e0d\u80fd\u6b63\u786e\u7684\u4f7f\u7528\u65f6\u949f\u4f7f\u80fd\u4fe1\u53f7\uff0c\u751a\u81f3\u53ef\u80fd\u5bfc\u81f4\u529f\u8017\u4e0d\u964d\u53cd\u589e\u3002<\/p>\n<h3>\u65f6\u949f\u4f7f\u80fd\u4fe1\u53f7\u4ece\u4f55\u800c\u6765\uff1f<\/h3>\n<p>\u65f6\u949f\u4fe1\u53f7\u4ece\u4f55\u800c\u6765\uff1f\u8fd9\u5176\u5b9e\u662f\u7b14\u8005\u770b\u5230\u65f6\u949f\u4f7f\u80fd\u4fe1\u53f7\u8fd9\u4e2a\u8bcd\u8bed\u4faf\u7684\u7b2c\u4e00\u53cd\u5e94\u3002\u4e0a\u8282\u8bf4\u7684\u590d\u4f4d\u4ee3\u7801\u5c1a\u4e14\u662f\u6211\u4eec\u81ea\u5df1\u624b\u5199\u51fa\u6765\u7684\uff0c\u4f46\u662f\u8fd9\u4e2a\u65f6\u949f\u4f7f\u80fd\u4fe1\u53f7\u7b14\u8005\u53ef\u4ee5\u8bf4\u662f\u95fb\u6240\u672a\u95fb\uff0c\u6240\u4ee5\u8fd8\u662f\u5f88\u6709\u5fc5\u8981\u4e86\u89e3\u4e00\u4e0b\u8fd9\u4e2a\u4fe1\u53f7\u5230\u5e95\u662f\u600e\u4e48\u6765\u7684\u3002<\/p>\n<p>\u624b\u518c\u4e0a\u8bf4\uff0c\u5982\u679c\u4f60\u5728\u65f6\u5e8f\u7535\u8def\u903b\u8f91\u4e2d\u5199\u4e86\u4e00\u6761\u5206\u652f\u4e0d\u5b8c\u6574\u7684\u6761\u4ef6\u8bed\u53e5\uff08\u901a\u4fd7\u6765\u8bf4\u5c31\u662f if \u6ca1\u5199 else \u5206\u652f\uff09\uff0c\u90a3\u4e48\u4e3a\u4e86\u4fdd\u8bc1\u5728 else \u7684\u60c5\u51b5\u4e2d\u5bc4\u5b58\u5668\u7684\u503c\u4e0d\u53d1\u751f\u53d8\u5316\uff0c\u7efc\u5408\u5668\u5c31\u4f1a\u7efc\u5408\u51fa\u4e00\u4e2a\u65f6\u949f\u4f7f\u80fd\u4fe1\u53f7\u3002\u6362\u53e5\u8bdd\u8bf4\uff1a\u65f6\u5e8f\u7535\u8def\u4e2d\u5bc4\u5b58\u5668\u7684\u503c\u53ea\u6709\u5728\u65f6\u949f\u8fb9\u6cbf\u624d\u4f1a\u66f4\u65b0\uff0c\u90a3\u6211\u628a\u65f6\u949f\u5173\u4e86\uff0c\u5c31\u4e0d\u4f1a\u66f4\u65b0\u4e86\uff08doge<\/p>\n<p>\u4e0d\u5f97\u4e0d\u8bf4\u8fd9\u90e8\u5206\u5185\u5bb9\u5bf9\u7b14\u8005\u6765\u8bf4\u6709\u70b9\u8d85\u7eb2\uff0c\u7b14\u8005\u4e00\u76f4\u4ee5\u4e3a\u6ca1\u6709\u5199\u7684 else \u4f1a\u88ab\u8865\u4e0a\u4e00\u53e5 <code>reg_name &lt;=reg_name<\/code>\uff0c\u6ca1\u60f3\u5230\u8fd9\u4e24\u8005\u5176\u5b9e\u8fd8\u662f\u4e0d\u4e00\u6837\u7684\u3002\u5f53\u7136\u6211\u4eec\u4e5f\u4e0d\u80fd\u542c\u98ce\u5c31\u662f\u96e8\uff0c\u6211\u4eec\u6574\u4e00\u6bb5\u7b80\u5355\u7684\u5c0f\u4ee3\u7801\u6765\u8bd5\u8bd5\u3002<\/p>\n<p>\u5148\u5199\u4e00\u6bb5 if \u5206\u652f\u5b8c\u6574\uff0c\u4e14\u5728\u7684\u4ee3\u7801\uff1a<\/p>\n<pre><code class=\"language-verilog\">module test (\n    input clk,\n\n    input a,\n    input b,\n\n    output reg c\n);\n\n    always @(posedge clk) begin\n        if (a) begin\n            c &lt;= b;\n        end else begin\n            c &lt;= 1;\n        end\n    end\n\nendmodule  \/\/ test\n\n<\/code><\/pre>\n<p>\u663e\u7136\u8fd9\u6bb5\u4ee3\u7801\u5e94\u8be5\u662f\u4e00\u4e2a\u53cc\u7aef\u53e3\u9009\u62e9\u5668\u7684\u7ed3\u6784\uff0c\u4e24\u4e2a\u8f93\u5165\u5f15\u811a\u5206\u522b\u63a5\u5230 b \u548c 1\uff0c\u9009\u62e9\u7aef\u53e3\u662f a\uff0c\u800c\u8f93\u51fa\u5219\u63a5\u5230\u4e00\u4e2a D \u89e6\u53d1\u5668\u4e0a\u6784\u6210\u4e00\u4e2a\u65f6\u5e8f\u7535\u8def\uff0c\u67e5\u770b\u7535\u8def\u7684\u8be6\u7ec6\u8bbe\u8ba1\u548c\u6211\u4eec\u7684\u6784\u60f3\u662f\u4e00\u81f4\u7684\uff1a<br \/>\n<div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/zhewana.cn\/wp-content\/uploads\/2024\/11\/Pasted-image-20241119234147.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/zhewana.cn\/wp-content\/uploads\/2024\/11\/Pasted-image-20241119234147.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"Pasted image 20241119234147.png\"><\/div><br \/>\n\u90a3\u4e48\u6211\u4eec\u6765\u770b\u770b\u5b9e\u9645\u7efc\u5408\u51fa\u6765\u7684\u539f\u7406\u56fe\u662f\u4ec0\u4e48\u6837\u7684\uff1a<br \/>\n<div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/zhewana.cn\/wp-content\/uploads\/2024\/11\/Pasted-image-20241119234502.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/zhewana.cn\/wp-content\/uploads\/2024\/11\/Pasted-image-20241119234502.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"Pasted image 20241119234502.png\"><\/div><br \/>\n\u629b\u5f00\u8f93\u5165\u8f93\u51fa\u7f13\u5b58\u7528\u7684 buff \u4e0d\u8c08\uff0c\u5b9e\u9645\u7684\u7535\u8def\u7ed3\u6784\u548c\u6211\u4eec\u6240\u6784\u601d\u7684\u7535\u8def\u7ed3\u6784\u662f\u7c7b\u4f3c\u7684\uff0c <a href=\"https:\/\/blog.csdn.net\/qq_42196515\/article\/details\/114110217\">FDRE\uff08\u5355 D \u89e6\u53d1\u5668\uff09<\/a>\u867d\u7136\u6709\u65f6\u949f\u4f7f\u80fd\u5f15\u811a\uff0c\u4f46\u662f\u65f6\u949f\u4f7f\u80fd\u662f\u76f4\u63a5\u62c9\u9ad8\u7684\uff0c\u5e76\u6ca1\u6709\u5bf9\u6211\u4eec\u7684\u63a7\u5236\u903b\u8f91\u6709\u4efb\u4f55\u5f71\u54cd\u3002<\/p>\n<p>\u90a3\u4e48\u6211\u4eec\u518d\u6765\u5bf9\u6bd4\u4e00\u4e0b\u6ca1\u6709 else \u7684\u4ee3\u7801\uff1a<\/p>\n<pre><code class=\"language-verilog\">module test (\n    input clk,\n\n    input a,\n    input b,\n\n    output reg c\n);\n\n    always @(posedge clk) begin\n        if (a) begin\n            c &lt;= b;\n        end\n    end\n\nendmodule  \/\/ test\n<\/code><\/pre>\n<p>\u8be6\u7ec6\u8bbe\u8ba1\u663e\u7136\u662f\u4e00\u4e2a D \u89e6\u53d1\u5668\u7684\u903b\u8f91\uff1a<br \/>\n<div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/zhewana.cn\/wp-content\/uploads\/2024\/11\/Pasted-image-20241120001341.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/zhewana.cn\/wp-content\/uploads\/2024\/11\/Pasted-image-20241120001341.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"Pasted image 20241120001341.png\"><\/div><br \/>\n\u800c\u5b9e\u9645\u7efc\u5408\u51fa\u6765\u7684\u539f\u7406\u56fe\u786e\u5b9e\u5982\u624b\u518c\u6240\u8bf4\uff0c\u5c06\u8f93\u5165\u4fe1\u53f7\u8fde\u63a5\u5230\u4e86\u65f6\u949f\u4f7f\u80fd\uff1a<br \/>\n<div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/zhewana.cn\/wp-content\/uploads\/2024\/11\/Pasted-image-20241120001521.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  decoding=\"async\" data-original=\"https:\/\/zhewana.cn\/wp-content\/uploads\/2024\/11\/Pasted-image-20241120001521.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"Pasted image 20241120001521.png\"><\/div><br \/>\n\u4e0d\u8fc7\u4e00\u4e2a\u6bd4\u8f83\u4ee4\u4eba\u56f0\u60d1\u7684\u70b9\u662f\u5f53\u5bc4\u5b58\u5668\u7684\u503c\u5728 else \u5206\u652f\u4e2d\u6ca1\u6709\u53d1\u751f\u53d8\u5316\u65f6\uff0c\u65e0\u8bba\u662f\u5426\u7701\u7565 else \u5206\u652f\u90fd\u4f1a\u5c06\u8f93\u5165\u8fde\u63a5\u5230\u65f6\u949f\u4f7f\u80fd\u4e0a\uff0c\u4e0d\u8fc7\u5927\u81f4\u7684\u884c\u4e3a\u4e5f\u7b97\u662f\u4e0e\u624b\u518c\u4e0a\u7684\u8bf4\u6cd5\u4e00\u81f4\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4f5c\u4e3a\u4e00\u4e2a\u4ece\u5d4c\u8f6f\u8dd1\u6765\u5b66 FPGA \u7684\u83dc\u9e1f\uff0c\u7b14\u8005\u6bcf\u6b21\u52a8\u624b\u5199 verilog \u4ee3\u7801\u7684\u65f6\u5019\u90fd\u6709\u4e00\u79cd\u5f88\u62e7\u5df4\u7684\u611f\u89c9\uff0c\u603b\u89c9\u7684 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[43],"tags":[],"class_list":["post-734","post","type-post","status-publish","format-standard","hentry","category-43"],"_links":{"self":[{"href":"https:\/\/zhewana.cn\/index.php?rest_route=\/wp\/v2\/posts\/734","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zhewana.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zhewana.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zhewana.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zhewana.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=734"}],"version-history":[{"count":2,"href":"https:\/\/zhewana.cn\/index.php?rest_route=\/wp\/v2\/posts\/734\/revisions"}],"predecessor-version":[{"id":736,"href":"https:\/\/zhewana.cn\/index.php?rest_route=\/wp\/v2\/posts\/734\/revisions\/736"}],"wp:attachment":[{"href":"https:\/\/zhewana.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=734"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zhewana.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=734"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zhewana.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=734"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}