灌水：proteus7.1中atmega16不能模拟奇偶校验

proteus Atmega16 help:
The USART is modelled as a UART only. Also the additional UART features such as parity and double rate clocking are not modelled.
所以，proteus中mega16没有做奇偶校验的模型，mega16无法模拟奇偶校验，只能模拟一般没有奇偶校验的串口。

根据proteus中示波器观察，当在程序中设了奇偶校验位之后，在模拟中串口输出波形缺少了奇偶校验那一位，其他位都没缺。