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JANUARY 2004
ST16C650A
2.90V TO 5.5V UART WITH 32-BYTE FIFO
REV. 5.0.0
GENERAL DESCRIPTION
The ST16C650A
1
(650A) is a 2.90 to 5.5 volt
Universal Asynchronous Receiver and Transmitter
(UART) with 5 volt tolerant inputs. This device
supports Intel and PC ISA mode data bus interfaces
and is software compatible to industry standard
16C450, 16C550, ST16C580 and ST16C650A
UARTs.
The 650A has 32 bytes of TX and RX FIFOs and is
capable of operating up to serial data rates of 3.125
Mbps at 5 volt supply voltage. The internal registers
include the 16C550 register set plus Exar’s enhanced
registers for additional features to support today’s
highly demanding data communication needs. The
enhanced features include automatic hardware and
software flow control, selectable TX and RX trigger
levels, and wireless infrared (IrDA) encoder/decoder.
The device provides a new capability to give user the
ability to program the wireless infrared encoder
output pulse width, hence reducing the power
consumption of a handheld unit.
The ST16C650A device comes in the 44-pin PLCC
and 48-pin TQFP packages in both the commercial
and industrial temperature ranges.
N
OTE
:
1 Covered by US patents #5,649,122.
FEATURES
Added features in top mark date code of "HC YYWW"
and newer:
s
s
s
s
s
s
s
2.90 to 5.5 Volt Operation
5 Volt Tolerant Inputs
Automatic RS485 Half-Duplex Control Output
Programmable Infrared Encoder Pulse Width
Sleep Mode with Wake-up Indicator
Device ID & Revision
Up to 3.125 Mbps Data Rate at 5 Volts
Added feature in top mark date code of "I2 YYWW"
and newer:
s
0 ns address hold time
•
Intel or PC Mode 8-bit Bus Interface
•
32-byte Transmit and Receive FIFOs
•
Automatic Hardware (RTS/CTS) Flow Control
•
Hardware Flow Control Hysteresis
•
Automatic Software (Xon/Xoff) Flow Control
APPLICATIONS
•
Battery Operated Electronics
•
Handheld Terminal
•
Personal Digital Assistants
•
Cellular Phones DataPort
•
Wireless Infrared Data Communications Systems
F
IGURE
1. B
LOCK
D
IAGRAM
RESET
32 Byte TX FIFO
A2:A0
Transmitter
D7:D0
IOR#
IOR
IOW#
IOW
CS2#
CS1
CS0
INT
TXRDY#
RDRDY#
DDIS#
BRG
Prescaler
SEL
S1
S2
S3
IRQA
IRQB
IRQC
Baud Rate Generator
PC Mode:
COM 1 to 4
Decode Logic
XTAL1/CLK
XTAL2
Intel,
Motorola
or PC
Data Bus
Interface
UART
Configuration
Regs
CTS Flow
Control
Modem Control Signals
RTS Flow
Control
DTR#, DSR#,
RTS#, CTS#,
CD#, RI#
Infrared Encoder and
Pulse Width Control
TX
Infrared
Decoder
RX
Receiver with Auto
Software Flow Control
32 Byte RX FIFO
Crystal Osc/Buffer
Exar
Corporation 48720 Kato Road, Fremont CA, 94538
•
(510) 668-7000
•
FAX (510) 668-7017
•
www.exar.com
EXAR [ EXAR CORPORATION ]
