AN4124 datasheet(7/32 Pages) STMICROELECTRONICS

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AN4124

HW/SW recoverability fault

Doc ID 023294 Rev 2

7/32

HW/SW recoverability fault

In general, the following definitions are applicable to fault management:

●

HW recoverable fault: the fault indication is a level sensitive signal that is asserted until

the cause of the fault is removed. Typically the fault signal is latched in an external

module to the FCCU. The FCCU state transitions are consequently executed on the

state changes of the input fault signal (fccu_cf[] or fccu_ncf[]). No SW intervention in

the FCCU is required to recover the fault condition.

●

SW recoverable fault: the fault indication is a signal asserted without a defined time

duration. The fault signal is resynchronized and latched in the FCCU. The fault

recovery is executed following a SW recovery procedure (status/flag register clearing).

The following types of reset are applicable:

●

Destructive reset: any type of reset related to a power failure condition that implies a

complete system reinitialization

●

Long functional reset: implies FLASH and digital circuitry (with some exceptions,

including FCCU, STCU) initialization

●

Short functional reset: implies digital circuitry (with some exceptions, including FCCU,

STCU) initialization

AN4124 Datasheet(PDF) 7 Page - STMicroelectronics