Setting the Serial Port Mode

Figure 9−1. Serial Port 0 Mode 0 Transmit Timing—High Speed Operation.

Figure 9−2. Serial Port Mode 0 Receive Timing—High Speed Operation.

9.2.2Serial Mode 1: Asynchronous Full-Duplex

In mode 1, serial data transfers are 10 bits long, full-duplex, and asynchronous. The transfer begins with a start bit, followed by eight bits of data (LSB first), then a stop bit. On receive, the stop bit is shifted into the RB8 bit in the SCON register. The baud rate is set by Timer 1 (UART 0 or 1) or Timer 2 (UART 0).

RXD is used for receiving data and TXD is used for transmitting data, LSB first. On reception, the stop bit goes into RB8 in the SCON register. Transmission is initiated by any instruction that writes to SBUF. The transmission begins after the first rollover of the divide-by-16 counter after the write. The SCONx.TIx interrupt flag is set two fOSC cycles after the stop bit has been transmitted.

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Texas Instruments MSC1210 manual 2. Serial Port Mode 0 Receive Timing-High Speed Operation