ST16C550
UART WITH 16-BYTE FIFO’s
April 2005
GENERAL DESCRIPTION
The ST16C550 (550) is a universal asynchronous re-
ceiver and transmitter with 16 byte transmit and receive
FIFO. It operates at 2.97 to 5.5 volts. A programmable
baud rate generator can select transmit and receive
clock rates from 50 bps to 1.5 Mbps.
The ST16C550 is an improved version of the NS16C550
UART with higher operating speed and lower access
time. The ST16C550 on board status registers provides
the error conditions, type and status of the transfer
operation being performed. Included is complete MO-
DEM control capability, and a processor interrupt
system that may be software tailored to the user’s
requirements. The ST16C550 provides internal loop-
back capability for on board diagnostic testing.
The ST16C550 is available in 40 pin PDIP, 44 pin PLCC,
and 48 pin TQFP packages. It is fabricated in an
advanced CMOS process to achieve low drain power
and high speed requirements.
PLCC Package
-DSR
41
-CTS
40
39
38
37
36
35
VCC
N.C.
-CD
42
-RI
43
D4
D3
D2
D1
D0
D5
D6
D7
RCLK
RX
N.C.
TX
CS0
CS1
-CS2
-BAUDOUT
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
44
6
5
4
3
2
1
RESET
-OP1
-DTR
-RTS
-OP2
N.C.
INT
-RXRDY
A0
A1
A2
ST16C550CJ44
34
33
32
31
30
29
XTAL1
XTAL2
-IOW
-IOR
-TXRDY
FEATURES
•
Pin to pin and functionally compatible to the Industry
Standard 16C550
•
2.97 to 5.5 volt operation
•
24MHz clock operation at 5V
•
16MHz clock operation at 3.3V
•
16 byte transmit FIFO
•
16 byte receive FIFO with error flags
•
Full duplex operation
•
Transmit and receive control
•
Four selectable receive FIFO interrupt trigger levels
•
Standard modem interface
•
Compatible with ST16C450
•
Low operating current ( 1.2mA typ.)
ORDERING INFORMATION
Part number
Package
Operating temperature
Device Status
ST16C550CP40
ST16C550CJ44
ST16C550CQ48
ST16C550IP40
ST16C550IJ44
ST16C550IQ48
40-Lead
44-Lead
48-Lead
40-Lead
44-Lead
48-Lead
PDIP
PLCC
TQFP
PDIP
PLCC
TQFP
0° C to + 70° C
0° C to + 70° C
0° C to + 70° C
-40° C to + 85° C
-40° C to + 85° C
-40° C to + 85° C
Active. See the ST16C550CQ48 for new designs.
Active
Active
Active. See the ST16C550IQ48 for new designs.
Active
Active
Rev. 5.01
EXAR
Corporation, 48720 Kato Road, Fremont, CA 94538
•
(510) 668-7000
•
FAX (510) 668-7017
-DDIS
IOW
GND
N.C.
IOR
-AS
EXAR [ EXAR CORPORATION ]
