IN16C554A Datasheet, PDF (1/31 Pages) IK Semicon Co., Ltd – Independent receiver clock input

1. Description
IN16C554A
Quadruple UART
February 2009 REV 1.01
IN16C554A is an enhanced quadruple version of the 16C550UART (Universal
Asynchronous Receiver Transmitter). IN16C554A is in part an upgrade version of
IN16C554, as it is designed for 3.3V only and has AUTO-CTS, AUTO-RTS functions.
In IN16C554A, Each channel can be put into FIFO mode to relieve the CPU of excessive
software overhead. In this mode, internal FIFOs are activated and 16 bytes plus 3 bit of
error data per byte can be stored in both receive and transmit modes.
Each channel performs serial-to-parallel conversion on data characters received from a
peripheral device or a MODEM, and parallel-to-serial conversion on data characters
received from the CPU. The CPU can read the complete status of the UART at any time
during the functional operation. The Status information includes the type and condition of
the transfer operations being performed by the UART, as well as any error conditions
such as parity, overrun, framing, and break interrupt.
IN16C554A includes a programmable baud rate generator which is capable of dividing the
timing reference clock input by divisors of 1 to 2¹⁶-1, and producing a 16x clock for driving
the internal transmitter logic. Provisions are also included to use this clock to drive the
receiver logic.IN16C554A has complete MODEM-control capability and an interrupt
system that can be programmed to the user’s requirements, minimizing the computing
required to handle the communication links. Moreover IN16C554A can select hardware
flow control. Hardware flow control significantly reduces software overhead and increases
system efficiency.
2. Features
■ In the FIFO mode, Each channel’s transmitter and receiver is buffered with 16-byte
FIFO to reduce the number of interrupts to CPU.
■ Adds or deletes standard asynchronous communication bits (start, stop, parity) to or
from the serial data.
■ Holding Register and Shift Register eliminate need for precise synchronization
between the CPU and serial data.
■ Independently controlled transmit, receive, line status and data interrupts.
■ Programmable Baud Rate Generators which allow division of any input reference
clock by 1 to 2¹⁶-1 and generate an internal 16X clock.
■ Independent receiver clock input
Modem control functions (CTS#, RTS#, DSR#, DTR#, RI#, and DCD#).
■ Fully programmable serial interface characteristics.
- 5-, 6-, 7-, or 8-bit characters
- Even-, Odd-, or No-Parity bit
1-, 1.5-, 2-Stop bit generation. ( Like other general UARTs, IN16C554 checks only
one stop bit, no matter how many they are)
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