ZHCSRW7 march 2023 AFE781H1 , AFE881H1
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 7-28 shows the UBM logical connections (through the isolation barrier, if used) for both minimum functionality (all optional pins disconnected) and maximum functionality (all pins connected).
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.