ST16C554/554D
2.97V TO 5.5V QUAD UART WITH 16-BYTE FIFO
JUNE 2006
REV. 4.0.1
GENERAL DESCRIPTION
The ST16C554/554D (554) is a quad Universal
Asynchronous Receiver and Transmitter (UART) with
16 bytes of transmit and receive FIFOs, selectable
receive FIFO trigger levels and data rates of up to 1.5
Mbps. Each UART has a set of registers that provide
the user with operating status and control, receiver
error indications, and modem serial interface
controls. An internal loopback capability allows
onboard diagnostics. The 554 is available in a 64-pin
LQFP and a 68-pin PLCC package. The 64-pin
package only offers the 16 mode interface, but the
68-pin package offers an additional 68 mode
interface which allows easy integration with Motorola
processors. The ST16C554CQ64 (64-pin) offers
three
state
interrupt
output
while
the
ST16C554DCQ64 provides continuous interrupt
output. The 554 combines the package interface
modes of the 16C554 and 68C554 on a single
integrated chip.
FEATURES
•
Pin-to-pin compatible with the industry standard
ST16C454,
ST68C454,
ST68C554,
TL16C554A and Philips’ SC16C554B
TI’s
•
Intel or Motorola Data Bus Interface select
•
Four independent UART channels
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Register Set Compatible to 16C550
Data rates of up to 1.5 Mbps at 5 V
Data rates of up to 500 Kbps at 3.3V
16 byte Transmit FIFO
16 byte Receive FIFO with error tags
4 Selectable RX FIFO Trigger Levels
Full modem interface
•
2.97V to 5.5V supply operation
•
Crystal oscillator or external clock input
APPLICATIONS
•
Portable Appliances
•
Telecommunication Network Routers
•
Ethernet Network Routers
•
Cellular Data Devices
•
Factory Automation and Process Controls
F
IGURE
1. ST16C554 B
LOCK
D
IAGRAM
A2:A0
D7:D0
IOR#
IOW#
CSA#
CSB#
CSC#
CSD#
INTA
INTB
INTC
INTD
TXRDY# A-D
RXRDY# A-D
Reset
16/ 68#
INTSEL
UART Channel D
(same as Channel A)
UART Channel A
UART 16 Byte TX FIFO
Regs
IR
TX & RX
ENDEC
BRG
16 Byte RX FIFO
UART Channel B
(same as Channel A)
UART Channel C
(same as Channel A)
2.97 V to 5.5 V VCC
GND
TXA, RXA, IRTXA, DTRA#,
DSRA#, RTSA#, CTSA#,
CDA#, RIA#
Data Bus
Interface
TXB, RXB, IRTXB, DTRB#,
DSRB#, RTSB#, CTSB#,
CDB#, RIB#
TXC, RXC, IRTXC, DTRC#,
DSRC#, RTSC#, CTSC#,
CDC#, RIC#
TXD, RXD, IRTXD, DTRD#,
DSRD#, RTSD#, CTSD#,
CDD#, RID#
XTAL1
XTAL2
Crystal Osc / Buffer
Exar
Corporation 48720 Kato Road, Fremont CA, 94538
•
(510) 668-7000
•
FAX (510) 668-7017
•
www.exar.com
EXAR [ EXAR CORPORATION ]
