ERTEC 200P GPIOs / XHIF
What is the intended use of the GPIOs?
In my opinion, the XHIF interface would give much more options and much lower latency for applications/carriers needing it, while also providing SPI and UART as alternative function.
Out of the 68 user IOs of LPC FMC connector, I would connect (if achievable, since some are already used for LEDs, etc.):
- 64 IOs to the XHIF, which can be used as XHIF or regular GPIOs, SPI master or slave, I2C, etc.
- 4 IOs to interrupt-capable pins (the ones that have the most interesting alternative functions).
Also one of the PLL outputs should be connected to a M2C clock pin, for synchronous applications on the carrier.
Finally the EXT_TRIGGER signal should be connected to a pin offering interesting alternative function, such as timer input.