Consider two 4-bit binary numbers A and B. Bits of A are a3, a2, a1, and a0, and bits of B are b3, b2, b1, and b0. A is greater than B if a3 is 1 and b3 is 0, but if a3 and b3 are the same, then if a2 is 1 and b2 is 0, we can determine that A is greater than B. This evaluation continues until a0 and b0 are considered. If a0 and b0 are equal then A and B are equal. Using discrete gates and Verilog gate primitives build a 4-bit comparator that generates a 1 on its GT output when its 4-bit input A is greater than its B input, and a 1 on its EQ output when A and B are equal. You must use the generate statement and other Verilog iterative logic support structures.
时间: 2023-12-24 14:02:56 浏览: 27
Here is a possible implementation of the 4-bit comparator in Verilog:
```
module comparator (
input [3:0] A,
input [3:0] B,
output reg GT,
output reg EQ
);
genvar i;
always @(*) begin
GT = 0;
EQ = 1;
for (i = 3; i >= 0; i = i - 1) begin
if (A[i] > B[i]) begin
GT = 1;
EQ = 0;
break;
end else if (A[i] < B[i]) begin
GT = 0;
EQ = 0;
break;
end
end
end
endmodule
```
The module takes two 4-bit inputs A and B, and generates two outputs: GT (greater than) and EQ (equal). The GT output is set to 1 if A is greater than B, and to 0 otherwise. The EQ output is set to 1 if A and B are equal, and to 0 otherwise.
The implementation uses a generate statement to loop through the bits of A and B, starting from the most significant bit (bit 3) and going down to the least significant bit (bit 0). For each bit, the module compares the corresponding bits of A and B, and sets the GT and EQ outputs accordingly. If A has a 1 and B has a 0 in a given bit position, then A is greater than B and the GT output is set to 1. If A has a 0 and B has a 1 in a given bit position, then A is less than B and the GT output is set to 0. If A and B have the same value in a given bit position, then the module moves on to the next bit and continues the comparison.
Note that this implementation uses combinational logic, so the GT and EQ outputs will be updated whenever the inputs A and B change. If you need to synchronize these outputs with a clock or other signals, you may need to add additional registers or timing constraints.