题解 | #全加器#
全加器
http://www.nowcoder.com/practice/d04c046febb74e72949baee9aa99d958
实现全加器①
根据全加器的功能，可列出功能表如下：
|
输入 |
输出 |
|||
|
A |
B |
Ci |
S |
Co |
|
0 |
0 |
0 |
0 |
0 |
|
0 |
0 |
1 |
1 |
0 |
|
0 |
1 |
0 |
1 |
0 |
|
0 |
1 |
1 |
0 |
1 |
|
1 |
0 |
0 |
1 |
0 |
|
1 |
0 |
1 |
0 |
1 |
|
1 |
1 |
0 |
0 |
1 |
|
1 |
1 |
1 |
1 |
1 |
module add_half( input A , input B , output wire S , output wire C ); assign S = A ^ B; assign C = A & B; endmodule /***************************************************************/ module add_full( input A , input B , input Ci , output wire S , output wire Co ); wire c_1; wire c_2; wire sum_1; add_half add_half_1( .A (A), .B (B), .S (sum_1), .C (c_1) ); add_half add_half_2( .A (sum_1), .B (Ci), .S (S), .C (c_2) ); assign Co = c_1 | c_2;
`timescale 1ns/1ns module add_half( input A , input B , output wire S , output wire C ); assign S = A ^ B; assign C = A & B; endmodule /***************************************************************/ module add_full( input A , input B , input Ci , output wire S , output wire Co ); wire c_1; wire c_2; wire sum_1; add_half add_half_1( .A (A), .B (B), .S (sum_1), .C (c_1) ); add_half add_half_2( .A (sum_1), .B (Ci), .S (S), .C (c_2) ); assign Co = c_1 | c_2; endmodule
