EXAR
Corporation, 48720 Kato Road, Fremont, CA 94538
(510) 668-7000
FAX (510) 668-7017
XR16C854
QUAD UART WITH RX/TX FIFO
COUNTERS,128-BYTE FIFO
Rev. 1.00P
PLCC Package
DESCRIPTION
The XR16C854
*
1
(854) is a universal asynchronous receiver and transmitter (UART) with a dual foot print
interface compatible with the ST16C554D/654 and ST68C554/654. The 854 is an enhanced UART with 128 byte
FIFOs, Independent Transmit and Receive FIFO counter, automatic hardware/software flow control, and data
rates up to 1.5Mbps. Onboard status registers provide the user with error indications and operational status,
modem interface control. System interrupts may be tailored to meet user requirements. An internal loop-back
capability allows onboard diagnostics. The 854 is available in 64 pin TQFP, 68 pin PLCC, and 100 pin QFP
packages. The 64 pin package offers the 16 interface mode which is compatible with the industry standard
ST16C554. The 68 and 100 pin packages offer an additional 68 mode which allows easy integration with Motorola,
and other popular microprocessors. The XR16C854CV (64 pin) offers three state interrupt control while the
XR16C854DV provides constant active interrupt outputs. The 64 pin devices do not offer TXRDY/RXRDY outputs
or the default clock select option (CLKSEL). The 100 pin packages offer faster channel status access by providing
separate outputs for TXRDY and RXRDY, offer separate Infrared TX outputs and a musical instrument clock input
(MIDICLK). The 854 combines the package interface modes of the 16C554/654 and 68C554/654 series on a
single integrated chip.
FEATURES
Compatibility with the Industry Standard
ST16C554/654, ST68C554/654, TL16C554
1.5 Mbps transmit/receive operation (24MHz)
128 byte transmit and receive FIFO
Independent transmit and receive FIFO counter
Automatic software/hardware flow control
Programmable Xon/Xoff characters
Software selectable Baud Rate Generator pre-
scaleable clock rates of 1X, 4X.
Four selectable, and Programmable Transmit/
Receive FIFO interrupt trigger levels
Standard modem interface or infrared IrDA en-
coder/decoder interface
Software flow control turned off optionally by any
(Xon) RX character
Independent MIDI interface on 100 pin packages
100 pin packages offer internal register FIFO
monitoring and separate IrDA TX outputs
Sleep mode ( 200
μ
A stand-by)
ORDERING INFORMATION
Part number
XR16C854CJ
XR16C854CV
XR16C854DCV
XR16C854CQ
Pins
68
64
64
100
Package Operating temperature
PLCC
0° C to + 70° C
TQFP
0° C to + 70° C
TQFP
0° C to + 70° C
QFP
0° C to + 70° C
Part number
XR16C854IJ
XR16C854IV
XR16C854DIV
XR16C854IQ
Note *1: Patent Pending
Pins
68
64
64
100
Package Operating temperature
PLCC
-40° C to + 85° C
TQFP
-40° C to + 85° C
TQFP
-40° C to + 85° C
QFP
-40° C to + 85° C
9
8
7
6
5
4
3
2
1
6
6
6
6
6
6
6
6
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
-DSRA
-CTSA
-DTRA
VCC
-RTSA
INTA
-CSA
TXA
-IOW
TXB
-CSB
INTB
-RTSB
GND
-DTRB
-CTSB
-DSRB
-
-
R
C
1
A
A
A
X
X
R
-
-
G
R
-
-
-DSRD
-CTSD
-DTRD
GND
-RTSD
INTD
-CSD
TXD
-IOR
TXC
-CSC
INTC
-RTSC
VCC
-DTRC
-CTSC
-DSRC
-
-
R
G
D
D
D
D
D
D
D
I
V
R
-
-
XR16C854CJ
16 MODE
Preliminary
Information