DESCRIPTION
The ST16C552/ST16C552A (552/552A) is a dual universal asynchronous receiver and transmitter (UART) with an added bi-directional parallel port that is directly compatible with a CENTRONICS type printer. The parallel port is designed such that the user can configure it as general purpose I/O interface, or for connection to other printer devices. The 552/552A provides enhanced UART functions with 16 byte FIFO’s, a modem control interface, and data rates up to 1.5Mbps. Onboard status registers provide the user with error indications and operational status.

FEATURES
Added features in device revision "F" and newer:
 • 5V Tolerant Inputs
 • Pin to pin and functional compatible to ST16C452/ 452PS, TL16C552
 • 2.97 to 5.5 volt operation
 • Software compatible with INS8250, NS16C550
 • 1.5 Mbps transmit/receive operation (24MHz)
 • 16 byte transmit FIFO
 • 16 byte receive FIFO with error flags
 • Independent transmit and receive control
 • Modem and printer status registers
 • UART port and printer port Bi-directional
 • Printer port direction set by single control bit or 8 bit pattern (AA/55)
 • Modem control signals (-CTS, -RTS, -DSR, -DTR, -RI, -CD)
 • Programmable character lengths (5, 6, 7, 8)
 • Even, odd, or no parity bit generation and detection
 • TTL compatible inputs, outputs
 • Power down mode