скорость какая надо? микрочип предлагает либу 8 портов на DMA:
Overview:
Up to 8 additional UARTs available with minimal CPU overhead
Up to 8 x TX channel
Up to 8 x RX channels
Different Baud rates for each RX and TX
Programmable Oversampling (5x..16x)
Majority ruling over central 3 samples is used for each bit
For each channel:FIFO buffers for each channel, programmable depth (default 8 char). Programmable n. bits(5..9), parity and n. stop bits. Optional hardware handshake (RTS/CTS). Optional RS485 support
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