Feature Request: Full FTDI Connection on Alchitry Cu


as I am now working with connecting the Alchitry Cu with my application I had a closer look on the FTDI-Chip. It is possible to do multiple modes as UART, SPI and parallel with it. On the schematic only two pins of the port B for communication with the FPGA are connected (usable for UART). It would be a very nice feature if the user can optionally connect the other pins to the FPGA (for example with jumpers or solder pads for 0 Ohm resistors). This would lead to a gain of data rate (if using parallel mode) if someone is trying to do something with high data throughput. Additionally communicating with SPI can be more simple to implement for beginners and makes it easier to migrate on a micro-controller application (relevant for hardware accelerators).

What do you think about it?

  • RRC

Hey RRC,

This was always a bit of a trade-off. Do you dedicate more pins to the USB port or keep more open for general use. You could do as you suggested and make solder jumpers but the vast majority of people will never touch this. You can reach “pretty good” speeds with the serial port, 12M baud IIRC, and it is easier to create tutorials/tools for a single type of interface.

To solve the use-cases where you need a ton of bandwidth, we will have the Ft out soon. This will support 200 mega bytes per second over USB 3.0 using an FT300.