DAN-133 Datasheet, PDF (8/8 Pages) Exar Corporation – EXAR’S QUARTS COMPARED

1.5 REPLACING THE TL16C554A WITH THE ST16C554, ST16C654 OR XR16C854
You can directly replace TI’s TL16C554A with Exar’s ST16C554, ST16C654 or XR16C854 with minimal
hardware changes if using the 68-PLCC package. The crystal oscillator circuitry should work in most cas-
es, but it may be necessary to modify the oscillator circuitry as shown in Figure 1. If replacing with the 64-
TQFP or 100-QFP packages, hardware changes will be required since the TL16C554A is not available in
those packages.
Replacing the TL16C554A with the ST16C554 is simple when the system is not using Automatic RTS/CTS
Hardware Flow Control.
If replacing the TL16C554A with the ST16C654 or XR16C854, minor software updates will be necessary
since Automatic RTS/CTS Hardware Flow Control is enabled differently for each QUART. Alos, it would
need to be updated in order to take advantage of the enhanced features of the ST16C654 and XR16C854
that are not available in the TL16C554A.
There should not be any timing problems replacing the TL16C554A with the ST16C554, ST16C654 or
XR16C854 because they are more flexible than the TL16C554A as described in the bus timing section.
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 2002 EXAR Corporation
June 2002
Send your UART technical inquiry with technical details to hotline: [e-mail]
Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.
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