8051 Serial Interface
TxD: Port 3, pin 1
- Transmit data shifted out
Full duplex: both operate in parallel
We will use Mode 1 only
- asynchronous
- 10 bit transfer: 1 start, 8 data, 1 stop
- Look at documentation for other modes
Clock for serial shift provided by timer 1
- i.e. programmable baud rate
- takes away a timer from other uses