ST16C1450 Datasheet, PDF (1/32 Pages) Exar Corporation – 2.97V TO 5.5V UART

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OCTOBER 2003
GENERAL DESCRIPTION
The ST16C1450, ST16C1451 series (here on
denoted as the 145X) is a universal asynchronous
receiver and transmitter (UART). The 145X is foot
print compatible to the SSI 73M1550 and SSI
73M2550 UART with one byte FIFO and higher
operating speed and lower access time. The 145X
provides enhanced UART functions with a modem
control interface, independent programmable baud
rate generators with clock rates to 1.5 Mbps. Onboard
status registers provide the user with error indications
and operational status. System interrupts and modem
control features may be tailored by external software
to meet specific user requirements. An internal loop-
back capability allows onboard diagnostics. The 145X
is available in a 28-pin PLCC/plastic-DIP, 48-pin
TQFP packages. The Baud rate generator can be
configured for either crystal or external clock input
with the exception of the 28 pin 1451 package. An
external clock must be provided for the 28 pin 1451
package. Each package type, with the exception of
the 28 pin 1450, provides a buffered reset output that
can be controlled through user software. The 145X is
fabricated in an advanced CMOS process to achieve
low drain power and high speed requirements. The
ST16C145X is not compatible with the industry
standard 16450 and will not work with the standard
serial port driver in MS Windows (see pages 15-16 for
details). For a MS Windows compatible UART, see
the ST16C450.
ST16C1450/51
2.97V TO 5.5V UART
FEATURES
REV. 4.2.0
• Pin and functionally compatible to SSI 73M1550/
2550
• 1 byte Transmit FIFO (THR)
• 1 byte Receive FIFO with error tags (RHR)
• Four levels of prioritized interrupts
• Modem Control Signals (CTS#, RTS#, DSR#,
DTR#, RI#, CD#)
• Programmable character lengths (5, 6, 7, 8) with
even, odd or no parity
• Crystal or external clock input (except 28 pin
ST16C1451, external clock only)
• 1.5 Mbps Transmit/Receive operation (24 MHz)
with programmable clock control
• Power Down Mode (50 uA at 3.3 V, 200 uA at 5 V)
• Software controllable reset output
• 2.97 to 5.5 Volt operation
APPLICATIONS
• Battery Operated Electronics
• Internet Appliances
• Handheld Terminal
• Personal Digital Assistants
• Cellular Phones DataPort
FIGURE 1. BLOCK DIAGRAM
A2:A0
D7:D0
IO R #
IOW #
CS#
IN T
RESET
RST
Data Bus
In te rfa c e
THR
T ra n s m itter
UART
C o n fig u ra tio n
Regs
M odem Control Signals
R e c e iv e r
RHR
Baud Rate Generator
Crystal Osc/Buffer
TX
DTR#, RTS#
DSR#, CTS#,
CD#, RI#
RX
XTAL1/CLK
XTAL2
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com