A $5 Pi Pico has two UARTS, but is not an FPGA; "Show HN: PicoVGA Library – VGA/TV Display on Raspberry Pi Pico" https://news.ycombinator.com/item?id=35117847#35120403
According to https://www.reddit.com/r/raspberrypipico/comments/1aut3l2/co... , pico-uart-bridge turns a pico into 6 TTL UARTs; https://github.com/Noltari/pico-uart-bridge