RS232奇偶校验的定义说明

ODD Parity bit set so that there is an odd number of 1 bits

EVEN Parity bit set so that there is an even number of 1 bits

NONE Parity bit is ignored, value is indeterminate

MARK Parity bit is ALWAYS set to 1

SPACE Parity bit is ALWAYS set to 0

 

sample:

 

在 ascii 字符"G"(0x47） 和"i"(0x049) 二进制等效项是 00100111 和 00101001。下表是一种方式一个奇偶校验位将进行编码的 （最后一位被用作奇偶校验位） 这些值：

   ODD   - 001001111     001010010
   EVEN  - 001001110     001010011
   NONE  - 00100111?     00101001?
   MARK  - 001001111     001010011
   SPACE - 001001110     001010010