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. Use the generate statement and other Verilog iterative logic support structures.
时间: 2023-12-22 18:02:41 浏览: 83
Here's one possible implementation of a 4-bit comparator in Verilog:
```
module comparator(A, B, GT, EQ);
input [3:0] A, B;
output GT, EQ;
wire [3:0] greater;
assign greater[3] = (A[3] == 1) && (B[3] == 0);
assign greater[2] = (A[3] == B[3]) && (A[2] == 1) && (B[2] == 0);
assign greater[1] = (A[3] == B[3]) && (A[2] == B[2]) && (A[1] == 1) && (B[1] == 0);
assign greater[0] = (A[3] == B[3]) && (A[2] == B[2]) && (A[1] == B[1]) && (A[0] == 1) && (B[0] == 0);
assign GT = greater[3] || greater[2] || greater[1] || greater[0];
assign EQ = (A == B);
endmodule
```
In this implementation, we first create a wire `greater` that stores whether each bit of A is greater than the corresponding bit of B according to the rules specified in the problem statement. We then combine these results using logical OR to determine if A is overall greater than B.
We also use the equality operator `==` to check if A and B are equal, and assign the result to the wire `EQ`.
Note that this implementation makes use of the `generate` statement implicitly by using the array index notation to generate the logic for each bit of the `greater` wire.
阅读全文