问 答 1: 有第9位,没有校验功能,自己算 答 2: 请问大侠8951 答 3: 请问大侠8951的p位真麽设置??8515好像是不能请问大侠8951的p位真麽设置??能否指教一下8515好像是不能 答 4: mega8有具体可以看看DataSheet的USART的Frame Formats等段 答 5: at90S系列无，MEGA系列都有 答 6: 90s8515串口可以选择第9位在UCR寄存器里设置CHR9 bit后，然后通过RXB8，TXB8位实现。但是校验位需要计算。
• Bit 2 – CHR9: 9-bit Characters
When this bit is set (one) transmitted and received characters are 9 bits long plus start and stop bits. The ninth bit is read and written by using the RXB8 and TXB8 bits in UCR, respectively. The ninth data bit CAN be used as an extra stop bit or a parity bit.
• Bit 1 – RXB8: Receive Data Bit 8
When CHR9 is set (one), RXB8 is the ninth data bit of the received character.
• Bit 0 – TXB8: Transmit Data Bit 8
When CHR9 is set (one), TXB8 is the ninth data bit in the character to be transmitted.