12ASX2 datasheet(49/147 Pages) INFINEON

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EiceDRIVER

™ SIL

1EDI2002AS

Functional Description

Datasheet

Rev. 3.1, 2015-07-30

Hardware Description

2.4.8

EN Signal Pin

The EN/FEN signal allows the logic on the primary side to have a direct control on the state of the device. A valid

signal has to be provided on this pin. A valid to invalid transition of the signal on pin EN/FEN generates an Event

Class A.

Pin EN/FEN should be driven actively by the external circuit. In case this pin is floating, an internal weak pull-down

resistor ensures that the signal is low.

Note: It should be noted that even if the signal at pin EN/FEN is valid, the device can still be in disabled state. This

may happen for example if another error is being detected

Depending on the value of bit PCFG2.FEN, two types of valid signals can be chosen from:

EN Mode

When the EN Mode is selected (bit PCFG2.FEN cleared), pin EN/FEN acts as an Enable pin. A valid EN/FEN

signal is defined as a digital High level. When EN/FEN is at Low level, the signal is considered as not valid and

the device is in Disabled State. In case of a High-to-Low transition, an Event Class A is generated.

FEN Mode

When the FEN Mode (bit PCFG2.FEN set) is selected, a valid signal is defined as a periodic clock signal. The

signal is constantly monitored by a watchdog unit. The watchdog evaluates the signal as valid if two consecutive

valid half-periods are detected.

If, after a valid signal has been recognized, a timing violation is detected by the watchdog, an Event Class A is

generated.

Every time an edge (rising or falling) is received, a counter is started. The counter is incremented at a frequency

of f

OSC1/8. The following edge is expected by the device during a window corresponding to the time between state

2 and state 6 of the counter. in case the edge comes too early or too late, an Event Class A is generated.

An Invalid to Valid transition of signal EN/FEN deactivates signals NFLTA and NFLTB (when the device is in

OPM3 or OPM5 only).

The levels read by the device at pin EN/FEN is given by bits PPIN.ENL. The validity status of EN/FEN signal is

given by bit PSTAT2.ENVAL.

2.4.9

Reset Events

A reset event sets the device and its internal logic in the default configuration. All user-defined settings are

overwritten with the default values. The list of reset events and their effect is summarized in Table 2-13.

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