ST16C650A_09 Datasheet, PDF (1/52 Pages) Exar Corporation – 2.90V TO 5.5V UART WITH 32-BYTE FIFO

ST16C650A
2.90V TO 5.5V UART WITH 32-BYTE FIFO
JUNE 2009
REV. 5.0.2
GENERAL DESCRIPTION
The ST16C650A¹ (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, and ST16C580 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.
NOTE: 1 Covered by US patents #5,649,122.
FEATURES
Added features in devices with a top mark date code
of "HC YYWW" and newer:
■ 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 devices with a top mark date code of
"I2 YYWW" and newer:
■ 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
FIGURE 1. BLOCK DIAGRAM
RESET
A2:A0
D7:D0
IOR#
IOR
IOW#
IOW
CS2#
CS1
CS0
INT
TXRDY#
RDRDY#
DDIS#
SEL
S1
S2
S3
IRQA
IRQB
IRQC
Intel or
PC Data
Bus
Interface
PC Mode:
COM 1 to 4
Decode Logic
UART
Configuration
Regs
BRG
Prescaler
32 Byte TX FIFO
Transmitter
Infrared Encoder and
Pulse Width Control
CTS Flow
Control
Modem Control Signals
RTS Flow
Control
Infrared
Decoder
Receiver with Auto
Software Flow Control
32 Byte RX FIFO
Baud Rate Generator
Crystal Osc/Buffer
TX
DTR#, DSR#,
RTS#, CTS#,
CD#, RI#
RX
XTAL1/CLK
XTAL2
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com