DAN-164 Datasheet, PDF (3/3 Pages) Exar Corporation – MIGRATING FROM THE ST16C2550 TO THE XR16L2750

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1.3 REPLACING THE ST16C2550 WITH THE XR16L2750
You can directly replace the ST16C2550 with the XR16L2750 in the 44-pin PLCC and 48-pin TQFP pack-
ages. In those packages, they are pin-to-pin compatible. If using the ST16C2550 in the 40-pin PDIP pack-
age, then hardware changes will be required since the XR16L2750 is not available in that package.
Since the internal registers of the XR16L2750 are the same as the ST16C2550, the XR16L2750 will work
with the same driver that is used with the ST16C2550 without any changes. However, to take advantage
of the enhanced features in the XR16L2750 such as the larger FIFO, Programmable Trigger Levels, FIFO
Level Counters, Auto Hardware Flow Control, Auto Software Flow Control and RS-485 Half-Duplex Con-
trol, the existing software needs to be modified.
In a nutshell, the ST16C2550 and XR16L2750 are very similar devices but with different FIFO sizes and
the XR16L2750 has some addtional features not found in the ST16C2550.
NOTICE
EXAR Corporation reserves the right to make changes to the products contained in this publication in order
to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of
any circuits described herein, conveys no license under any patent or other right, and makes no represen-
tation that the circuits are free of patent infringement. Charts and schedules contained here in are only for
illustration purposes and may vary depending upon a user’s specific application. While the information in
this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies.
EXAR Corporation does not recommend the use of any of its products in life support applications where
the failure or malfunction of the product can reasonably be expected to cause failure of the life support sys-
tem or to significantly affect its safety or effectiveness. Products are not authorized for use in such applica-
tions unless EXAR Corporation receives, in writing, assurances to its satisfaction that: (a) the risk of injury
or damage has been minimized; (b) the user assumes all such risks; (c) potential liability of EXAR Corpo-
ration is adequately protected under the circumstances.
Copyright 2005 EXAR Corporation
January 2005
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