A digitaladder needs more circuitry, and thus more power, to operate, but it does not require such high accuracy.
数字加法器需要更多的电路、因而需要更大的功率才能工作，但它不需要这么高的准确性。
2
We take the Full Adder as an example to introduce the use of VHDL in the design of digital system, the experiment of digital circuit and the teaching.
本文以全加器为例介绍其在数字系统设计和数字电路实验及教学中的应用。
3
The phase adder in the model is widely applied which could enable system to hold high frequency revolution, fast frequency switching, and easily digital modulating of the signal's phase and amplitude.