用2片4位加法器实现可控累加（加/减，-9到9，步长为3）电路，最大和两位10进制数99。-Controlled multiplier- with two 4-bit adder controllable accumulate (plus/minus,-9 to 9, step 3) circuit, the maximum and two decimal 99.

用labview制作的加法器，可以对数进行加法运算-Made of labview adder, can be add operation log

数字电路的8位加法器哦上传上来互相学习学习(The 8 bit adder of digital circuit is uploaded to learn from each other)