Specifications

mikroElektronika | Free Online Book | PIC Microcontrollers | Chapter 6: Serial Communication Modules
EUSART Asynchronous Mode
The EUSART transmits and receives data using standard non-return-to-zero (NRZ) format. As seen in figure 6-2 below, this
mode does not use clock signal, while the data format being transferred is very simple:
Fig. 6-2 EUSART Asynchronous Mode
Briefly, each data is transferred in the following way:
● In idle state, data line has high logic level (1);
● Each data transmission starts with START bit which is always a zero (0);
● Each data is 8- or 9-bit wide (LSB bit is first transferred); and
● Each data transmission ends with STOP bit which always has logic level which is always a one (1).
EUSART Asynchronous Transmitter
Fig. 6-3 EUSART Asynchronous Transmitter
In order to enable data transmission via EUSART module, it is necessary to configure it to operate as a transmitter. In
other words, it is necessary to define the state of the following bits:
TXEN = 1 - EUSART transmitter is enabled by setting this bit of the TXSTA register;
SYNC = 0 - EUSART is configured to operate in asynchronous mode by clearing this bit of the TXSTA register; and
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