Descriptions The GM16C550 is an asynchronous communi- cations element (ACE) that is functionally equivalent to the GM16C450, and addition-ally incorporates a 16byte FIFOs are available on both the transmitter and receiver, and can be activated by placing the device in the FIFO mode. After a reset, the registers of the GM16C550 are identical to those of the GM16C450. The UART performs serial-to-parallel conver- sion on data characters received from a peri-pheral device or a MODEM, and parallel-to- serial conversion on data characters received from the CPU. The CPU can read the com- plete status of the UART at any time during the functional operation. Status information reported includes the type and condition of the transfer operations being performed by the UART, as well as any error conditions (parity, overrun, framing, or break interrupt).