JAJSNU3 December 2023 AFE782H1 , AFE882H1
PRODUCTION DATA
In this mode, communicate with the integrated HART modem using the UART while communicating with the DAC using the SPI. Many discrete DACs use SPI communication, whereas HART modems use UART communication, but this special communication interface enables easy transition from discrete to integrated HART architecture. Figure 6-28 shows the UBM logical connections (through the isolation barrier, if used) for both minimum communication functionality (all optional communication pins disconnected, most GPIO pins available shown) and maximum communication functionality (all communication pins connected, least GPIO pins available shown). Enable each GPIO pin for use through proper register configuration. If a pin remains unused, tie the pin to either IOVDD using a pullup or to GND using a pulldown as indicated to avoid floating I/Os.
To setup the device in SPI plus UART mode using the SPI, set CONFIG.UART_BAUD = 0 to set the baud rate to 1200 for the UART, and to track the HART baud rate of 1200. The UART also works at a 9600 baud, but the 1200 baud rate of HART must be considered, and the FIFO STATUS must be monitored through the SPI.