The TL16PIR552 has a dual-channel universal asynchronous receiver/transmitter (UART). The UART is similar to the TL16C550C. The device serves two serial input/output ports simultaneously in microcomputer or microprocessor-based systems. Each channel performs serial-to-parallel conversion on data characters received from peripheral devices or modems and parallel-to-serial conversion on data characters transmitted by the CPU. The complete status of each channel of the dual UART can be read by the CPU at any time during functional operation. The information obtained includes the type and condition of the transfer operation being performed and the error condition.

The receiver and transmitter FIFOs in the UARTs store up to 16 bytes including three additional bits of error status per byte for the receiver FIFO.