That syntax is called anindexed part-select. The first term is the bit offset and the second term is the width. It allows you to specify a variable for the offset, but the width must be constant. Example from the SystemVerilog 2012 LRM: logic [31:0] a_vect; logic [0:31] b_vect;...
// We can't part-select multiple bits without an error, but we can select one bit at a time, // four times, then concatenate them together. assign out = {in[sel*4+3], in[sel*4+2], in[sel*4+1], in[sel*4+0]}; // Alternatively, "indexed vector part select" works better,...
ncvlog: *E,NOPSOM (ShiftRegister.sv,27|28): Part-select or indexed part-select cannot be applied to memory [4.2.2(IEEE)]. module worklib.ShiftRegister:sv errors: 2, warnings: 0 I believe the instruction is correct, so I think this System...
"indexed vector part select" works better, but has an unfamiliar syntax: // assign out = in[sel*4 +: 4]; // Select starting at index "sel*4", then select a total width of 4 bits with increasing (+:) index number.
Secondly, the "range" select problem can be solved in Verilog by a construct called indexed part select, see an example from Std IEEE 1364, particularly the last line: reg big_vect; reg little_vect; reg dword; integer sel; big_vect // == big_vect big_vect // == big_vect little...
Indexed vector part selects 在Verilog-1995中,可以选择向量的任一位输出,也可以选择向量的连续几位输出,不过此时连续几位的始末数值的index需要是常量。而在Verilog-2001中,可以用变量作为index,进行part select。 [base_expr+:width_expr] //positive offset [base_expr-:width_expr] //negative offset 其中base...
其形式如下索引的部分选择（indexedpart-select）。其形式如下：）。其形式如下：reg[15:0]big_vect;reg[0:15]little_vect;big_vect[lsb_base_expr+:width_expr]little_vect[msb_base_expr+:width_expr]big_vect[msb_base_expr-:width_expr]little_vect[lsb_base_expr-:width_expr]4、矩阵的扩展、Verilog-...
this is the so-called "Indexed vector part selects" 在Verilog-1995中,可以选择向量的任一位输出,也可以选择向量的连续几位输出,不过此时连续几位的始末数值的index需要是常量。而在Verilog-2001中,可以用变量作为index,进行part select。 [base_expr +: width_expr] //positive offset ...
this is the so-called "Indexed vector part selects" 在Verilog-1995中,可以选择向量的任一位输出,也可以选择向量的连续几位输出,不过此时连续几位的始末数值的index需要是常量。而在Verilog-2001中,可以用变量作为index,进行part select。 [base_expr +: width_expr] //positive offset ...
Nov.23.2005 Fixed bug of bit length evaluation in parameter Fixed bug of signed operation in parameter Fixed bug of indexed/partselect in system task/function Fixed bug of signed operation in parameter Fixed bug 1.86A-compiler crash PreprocessorUndefined...