TL16C554PN (Texas Instruments) is a quadruple UART (asynchronous communications element, ACE) with 16-byte FIFOs per channel, an enhanced quad version of the TL16C550, in an 80-pin (PN) package.

• Four improved TL16C550 ACEs plus steering logic · 16-byte FIFO in the transmitter and receiver of each channel
• Up to 16 MHz clock rate for up to 1 Mbaud operation · programmable baud rate generators (divisor of 1 to 216 − 1)
• 5-, 6-, 7- or 8-bit characters · even, odd or no parity · 1, 1 1/2 or 2 stop bits
• False start bit detection · complete status reporting · internal diagnostic loopback · 0 to 70 °C range

Data per Texas Instruments TL16C554, TL16C554I datasheet.