PGA460: Interfacing multiple PGA460 to single MSP430F5529 Launchpad

Hi Nishant,

You have two options of interfacing multiple PGA460 devices to a single master: bus or point-to-point (p2p).

The bus topology allows you to use a single UART or SPI port to connect all four PGA460 devices to. This is made possible by the PGA460's three bit UART_ADDR, which allows up to eight devices to share a single bus. On the bus, you can then target your communication to a single address for single device communication, or send synchronized broadcast commands, which target all devices on the bus. The limitation of the bus topology is that there is no synchronized command to tell one device to burst, while the others listen. For a single sensor-burst and all others listen on a bus, you will need to implement a software workaround to initiate a broadcast listen-only command, then send a single address burst-and-listen command to one device. See PGA460 FAQ #5.5 "Can I evaluate multiple PGA460 devices using the same UART bus of the PGA460-Q1 EVM?" for details on bus evaluation using the EVM/GUI: www.ti.com/.../slaa733.pdf

The p2p allocates a UART or SPI port from the microcontroller to each PGA460 device. This prevents having to maintain the UART_ADDR overhead, and only single address commands can be sent. For synchronized commands, the single address commands can be sent in parallel to each other by the master controller to allow for the single sensor burst and all others listen implementation. The drawback is that you will need a more costly microcontroller.