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Number $133B
ShortDesc Sends byte to serial port. If read, tells if data in RX buffer
Bit Mask %0001 0011 0011 1011 ??
Readable Yes
Writable Yes
Subsystem UART

Write to this port sends the byte to serial port (routed to WiFi module connector). Read from this port returns 0 if there are bytes to read in RX FIFO buffer, or 1 if no RX data.