xr16l2552im Exar Corporation, xr16l2552im Datasheet - Page 11

• Manufacturer Part Number: xr16l2552im
• Description: Industry Smallest Package Uart With 2.25v To 5.5v Operation
• Manufacturer: Exar Corporation

xr
REV. 1.1.1
To obtain maximum data rate, it is necessary to use full rail swing on the clock input. See external clock
operating frequency over power supply voltage chart in
The L2552 divides the basic external clock by 16. The basic 16X clock provides table rates to support standard
and custom applications using the same system design. The Baud Rate Generator divides this 16X clock by
any divisor from 1 to 2
Customized Baud Rates can be achieved by selecting the proper divisor values for the MSB and LSB sections
of baud rate generator.
Table 5
rate. When using a non-standard frequency crystal or external clock, the divisor value can be calculated for
DLL/DLM with the following equation.
O
UTPUT
MCR Bit-7=0
19.2k
38.4k
76.8k
shows the standard data rates available with a 14.7456 MHz crystal or external clock at 16X sampling
2400
4800
9600
400
Data Rate
T
ABLE
divisor (decimal) = (XTAL1 or External clock frequency ) / (serial data rate x 16)
5: T
Clock (Decimal)
D
IVISOR FOR
16
YPICAL DATA RATES WITH A
-1. The rate table is configured via the DLL and DLM internal register functions.
2304
384
192
F
TOR ON
96
48
24
12
IGURE
16x
6. O
XTAL2
80
70
60
50
40
30
Operating frequency for XR16L2552
with external clock and a 2K ohms
D
PERATING
IVISOR FOR
Clock (HEX)
pull-up resistor on XTAL2 pin.
PIN TO INCREASE OPERATING SPEED
3.0
900
180
C0
0C
60
30
18
3.5 4.0
F
Suppy Voltage
16x
14.7456 MH
REQUENCY
11
Figure
4.5
DLM P
V
ALUE
6.
C
5.0
2.25V TO 5.5V DUART WITH 16-BYTE FIFO
Z CRYSTAL OR EXTERNAL CLOCK
HART
09
01
00
00
00
00
00
ROGRAM
(HEX)
5.5
-40
. R
25
85
o
o
o
C
C
C
EQUIRES A
DLL P
V
ALUE
C0
0C
00
80
60
30
18
ROGRAM
2K
(HEX)
OHMS PULL
D
XR16L2552
E
ATA
-
RROR
UP RESIS
0
0
0
0
0
0
0
R
ATE
(%)
-