NXP Semiconductors freescale KV4 Series, Reference Manual

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41.3.3 Index Input (INDEX)
Normally connected to the index pulse output of a quadrature encoder, this pulse can
optionally reset the position counter and the pulse accumulator of the quadrature decoder
module. It also causes a change of state on the revolution counter. The direction of this
change, increment or decrement, is calculated from the PHASEA and PHASEB inputs.
The INDEX input can also be an input capture channel for one of the timer modules via
the Crossbar module (XBAR).
41.3.4 Home Switch Input (HOME)
The HOME input can be used by the quadrature decoder and the timer module. This input
can be used to trigger the initialization of the position counters (UPOS and LPOS). Often
this signal is connected to a sensor signaling the motor or machine, sending notification
that it has reached a defined home position.
This general purpose signal can also be connected to the timer module via the Crossbar
module (XBAR).
41.3.5 Trigger Input (TRIGGER)
The TRIGGER input can be used to clear the position counters (UPOS and LPOS) or to
take a snapshot of the POS, REV, and POSD registers. Often this signal is connected to a
periodic pulse generator or timer to indicate an elapsed time period.
41.3.6 Position Match Output (POSMATCH)
The POSMATCH output can be used to trigger a timer channel to record the time at
which the position of the shaft matches the user defined compare value (COMP).
Alternatively, it can be used to indicate when the position counters (UPOS and LPOS),
revolution counter (REV), or position difference counter (POSD) registers are read in
order to trigger a timer channel to record the time at which the position information was
read.
Chapter 41 Quadrature Encoder/Decoder (ENC)
KV4x Reference Manual, Rev. 2, 02/2015
Freescale Semiconductor, Inc.
Preliminary
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