128-byte FIFO — why it matters for interrupt service
A 128-byte FIFO per channel absorbs serial data bursts without immediate CPU attention, reducing overrun risk when the host is busy.
RS232 and RS485 on the same chip
Each of the four channels can be configured for RS232 or RS485, so one part covers both legacy point-to-point and multi-drop industrial buses. The auto flow control and IrDA encoder/decoder are built in — no external logic needed for hardware handshake or infrared serial links. That saves board area and BOM count in a panel controller or gateway that talks to multiple serial devices.