AN1015 Datasheet, PDF (1/19 Pages) STMicroelectronics – Software techniques for improving microcontrollers EMC performance

AN1015
Application note
Software techniques for improving microcontrollers EMC performance
Introduction
A major contributor to improved EMC performance in microcontroller-based electronics
systems is the design of hardened software.
Problems induced by EMC disturbances need to be considered as early as possible in the
design phase. EMC-oriented software increases the security and the reliability of your
application. EMC-hardened software is inexpensive to implement, improves the final goods
immunity performance and saves hardware and development costs. You should consider
EMC disturbances to analog or digital data just like any other application parameter.
Examples of problems induced by EMC disturbances:
 Microcontroller not responding
 Program Counter runaway
 Execution of unexpected instructions
 Bad address pointing
 Bad execution of subroutines
 Parasitic reset and/or parasitic interrupts
 Corruption of IP configuration
 I/O deprogramming
Examples of consequences of failing software:
 Unexpected response of product
 Loss of context
 Unexpected branch in process
 Loss of interrupts
 Loss of data integrity
 Corrupted reading of input values.
This application note deals with two categories of software techniques, namely:
 Preventive techniques: these can be implemented in existing designs, their purpose is to
improve product robustness.
 Auto-recovery techniques: when a runaway condition is detected, a recovery subroutine
is used to take the decision to execute fail-safe routines, optionally sending a warning and
then automatically returning back to normal operations (this operation may be absolutely
transparent to the user of the application).
June 2014
DocID5833 Rev 2
1/19
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