Atmel SAM4S-EK2 Atmel ATSAM4S-EK2 ATSAM4S-EK2 Data Sheet

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SAM4S [DATASHEET]

11100E–ATARM–24-Jul-13

Input filtering can efficiently remove spurious pulses that might be generated by the presence of particulate
contamination on the optical or magnetic disk of the rotary sensor.

Spurious pulses can also occur in environments with high levels of electro-magnetic interference. Or, simply if vibration
occurs even when rotation is fully stopped and the shaft of the motor is in such a position that the beginning of one of the
reflective or magnetic bars on the rotary sensor disk is aligned with the light or magnetic (Hall) receiver cell of the rotary
sensor. Any vibration can make the PHA, PHB signals toggle for a short duration.

1

1

1

MAXFILT

PHA

PHB

IDX

TIOA0

TIOB0

TIOB1

INVA

1

INVB

1

INVIDX

SWAP

1

IDXPHB

Filter

Filter

Filter

1

FILTER

Direction
and 
Edge
Detection

IDX

PHedge

DIR

Input Pre-Processing