ST16C2550 Datasheet, PDF (1/34 Pages) Exar Corporation – DUAL UART WITH 16-BYTE TRANSMIT AND RECEIVE FIFOS

ST16C2550
DUAL UART WITH 16-BYTE TRANSMIT
AND RECEIVE FIFO’S
DESCRIPTION
The ST16C2550 (2550) is a dual universal asynchronous receiver and transmitter (UART). The ST16C2550 is
an improved version of the NS16C550 UART with higher operating speed and lower access time. The 2550
provides enhanced UART functions with 16 byte FIFO’s, a modem control interface, and data rates up to 1.5Mbps.
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. Independent programmable baud rate generators are provided to
select transmit and receive clock rates from 50 Bps to 1.5 Mbps. The Baud rate generator can be configured for
either crystal or external clock input. The 2550 is available in a 40-pin plastic-DIP, 44-pin PLCC, and 48-pin TQFP
packages. The 40 pin package does not offer TXRDY and RXRDY pins (DMA Signal monitoring). Otherwise the
three package versions are the same. The 2550 is functionally compatible with the 16C2450. The 2550 is
fabricated in an advanced CMOS process to achieve low drain power and high speed requirements.
FEATURES
• Pin and functionally compatible to ST16C2450/
Software compatible with INS8250, NS16C550
• 1.5Mbps transmit/receive operation (24MHz
Max.)
• 16 byte transmit FIFO to reduce the bandwidth
requirement of the external CPU.
• 16 byte receive FIFO with error flags to reduce the
bandwidth requirement of the external CPU.
• Independent transmit and receive UART control
• Four selectable Receive FIFO interrupt trigger
levels
• Modem control signals (-CTS, -RTS, -DSR, -DTR,
-RI, -CD, and Software controllable line break)
• Programmable character lengths (5, 6, 7, 8) with
Even, odd, or no parity
• Status report register
• Crystal or external clock input
• 460.8 Kbps transmit/receive operation with 7.3728
MHz crystal or external clock source
• TTL compatible inputs, outputs
D5 7
D6 8
D7 9
RXB 10
RXA 11
-TXRDYB 12
TXA 13
TXB 14
-OPB 15
-CSA 16
-CSB 17
PLCC Package
ST16C2550CJ44
39 RESET
38 -DTRB
37 -DTRA
36 -RTSA
35 -OPA
34 -RXRDYA
33 INTA
32 INTB
31 A0
30 A1
29 A2
ORDERING INFORMATION
Part number
Pins Package
ST16C2550CP40 40 PDIP
ST16C2550CJ44 44 PLCC
ST16C2550CQ48 48 TQFP
Operating temperature
0° C to + 70° C
0° C to + 70° C
0° C to + 70° C
Part number
ST16C2550IP40
ST16C2550IJ44
ST16C2550IQ48
Pins Package
40 PDIP
44 PLCC
48 TQFP
Operating temperature
-40° C to + 85° C
-40° C to + 85° C
-40° C to + 85° C
Rev. 3.20
EXAR Corporation, 48720 Kato Road, Fremont, CA 94538 • [phone] • FAX [phone]