一,半加器


二,全加器
三位输入表决器



三位输入异或门


Note: Many authorities contend that the shaped XOR gate's behavior should correspond to the odd parity gate, but there is not agreement on this point. Logisim's default behavior for XOR gates is based on the IEEE 91 standard. It is also consistent with the intuitive meaning underlying the term exclusive or: A waiter asking whether you want a side dish of mashed potatoes, carrots, peas, or cole slaw will only accept one choice, not three, whatever some authorities may tell you. (I must admit, though, that I have not subjected this statement to a rigorous test.) You can configure the XOR and XNOR gates to use parity by changing its Multiple-Input Behavior
attribute.

一位全加器


四位全加器


同理,可以继续扩展到8位、16位、甚至32位的加法器。
八位加法器




0xAA + 0xBB = 0x165
