verilog一些操作符和特殊函数

还是写下来，用的少记不住

1.verilog +：

reg [31:0] dword;

reg [7:0] byte0;

reg [7:0] byte1;

reg [7:0] byte2;

reg [7:0] byte3;

assign byte0 = dword[0 +: 8]; // Same as dword[7:0]

assign byte1 = dword[8 +: 8]; // Same as dword[15:8]

assign byte2 = dword[16 +: 8]; // Same as dword[23:16]

assign byte3 = dword[24 +: 8]; // Same as dword[31:24]

2.clog2

//$clog2(x)是将x取以2为底的对数并且向上取整

temp = $clog2(1); //0

temp = $clog2(2);  //1

temp = $clog2(3);  //2

temp = $clog2(4);  //2

temp = $clog2(5);  //3

temp = $clog2(6);  //3