AN2523 Datasheet, PDF (1/23 Pages) STMicroelectronics – Migrating from STR91xF to STR91xFA

AN2523
Application note
Migrating from STR91xF to STR91xFA
Introduction
STR9 microcontrollers have two major salestype groups, as follows:
● The initial group consist of devices STR91xFxxxxx, for example STR912FW44X6, with
silicon revisions B, and D. Revision D is in production. Detailed technical information for
these devices may be found in the STR91xF datasheet, STR91xF reference manual,
and STR91xF errata documents.
● The second group consists of devices STR91xFAxxxxx, for example
STR912FAW44X6, with revisions E and G. Revision G is in production. Detailed
technical information for these devices may be found in the STR91xFA datasheet and
STR91xFA reference manual documents.
This document describes at the system level the feature enhancements and silicon fixes
incorporated in the new STR91xFA devices, compared to the original STR91xF devices.
It also describes what are the impacts when the STR91xF is replaced with the STR91xFA in
your design.
The changes in the STR91xFA can be grouped into two categories:
● changes that are needed to fix the functional issues in the STR91xF
● changes that are feature enhancements to the STR91xF
The enhancements are new features and will have no impact in your existing STR91xF
design. You have the option to add these new features to your design or not using it at all.
The functional or silicon fixes in the STR91xFA are targeted at solving the problems that are
documented in the STR91xF Errata Sheet. If you have implemented software workaround
on some of the issues, the workarounds will work fine with the STR91xFA and no software
change is required. Below is a summary of the changes, followed by detail descriptions.
May 2007
Rev 2
1/23
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