Verilog刷题笔记5

题目：

A Bit of Practice One common place to see a replication operator iswhen sign-extending a smaller number to a larger one, while preserving its signed value. This is done by replicating the sign bit (the most significant bit) of the smaller number to the left. For example, sign-extending 4’b0101 (5) to 8 bits results in 8’b00000101 (5), while sign-extending 4’b1101 (-3) to 8 bits results in 8’b11111101 (-3).
Build a circuit that sign-extends an 8-bit number to 32 bits. This
requires a concatenation of 24 copies of the sign bit (i.e., replicate bit[7] 24 times) followed by the 8-bit number itself.

我的解法：

module top_module (
    input [7:0] in,
    output [31:0] out );//

    // assign out = { replicate-sign-bit , the-input };
    assign out={{24{in[7]}},in};
endmodule

结果正确：