© 2014 Exar Corporation
XR21B1424IV64-0A-EVB
Evaluation Board User’s Manual
exar.com/XR21B1421
Rev 1A
1 / 6
Introduction
This user’s manual is for the XR21B1424IV64-0A-EVB evaluation board. The XR21B1424IV64-F shares a common evalua-
tion board with the XR21B1422IL40-F. The main difference between the XR21B1424IV64-F and the XR21B1422IL40-F is
the number of UART channels. The XR21B1424IV64-F has 4 UART channels. The XR21B1422IL40-F has 2 UART chan-
nels. The only USB UART device installed on the XR21B1424IV64-0A-EVB evaluation board is the XR21B1424IV64-F.
Evaluation Board Overview
A block diagram of the evaluation board is shown in
Figure 1
below.
Figure 1: Evaluation Board Block Diagram
In addition to the XR21B1424IV64-F, there are Exar SP339 Multiprotocol transceivers on this evaluation board. The SP339
can be configured for Loopback, RS-232, Half-Duplex RS-485 or Full-Duplex RS-485/422 Modes. The default setting when
shipped from the factory is RS-232 mode.
Figure 2
on the next page show the top view and bottom view of the evaluation board with all of the components, connectors
and headers labeled. A higher resolution PDF file for the top and bottom views are also included on the CD that is shipped
with the evaluation board.
Table 1: Evaluation Board Ordering Part Numbers
Device Ordering Part Number
Evaluation Board Ordering Part
Number
Device Package
Device
Location
XR21B1424IV64-F
XR21B1424IV64-0A-EVB
64-pin LQFP
U7
XR21B1422IL40-F
XR21B1422IL40-0A-EVB
40-pin QFN
U6
XR21B1424
SP338
SP339
USB
Connector
DB9
Connector
SP338
SP339
DB9
Connector
SP338
SP339
DB9
Connector
SP338
SP339
DB9
Connector
