10.0 Introduction


The Universal Asynchronous Receiver Transmitter (UART) module is the basic serial I/O module available in the dsPIC30F device family. The UART is a full-duplex asynchronous system that can communicate with peripheral devices, such as personal computers, RS-232, and RS-485 interfaces.

The primary features of the UART module are:

  • Full-duplex 8- or 9-bit data transmission through the UxTX and UxRX pins,
  • For 8-bit data even, odd, or no parity options,
  • One or two STOP bits,
  • Fully integrated Baud-rate generator with 16-bit prescaler,
  • 4-deep First-In-First-Out (FIFO) transmit data buffer,
  • 4-deep FIFO receive data buffer,
  • Parity, framing and buffer overrun error detection,
  • Support for 9-bit mode with address detect (9th bit=1),
  • Transmit and receive interrupts,
  • Loop-back mode for diagnostic support.

Each dsPIC30F device variant may have one or more UART modules (e.g. dsPIC30F4013 has 2 UART modules).

Fig. 10-1 shows a simplified block diagram of the UART module. The UART module consists of the three key hardware elements: Baud-rate generator, asynchronous transmitter, and asynchronous receiver.


Fig. 10-1 UART simplified block diagram