Micronas SDA 6000, User Manual

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SDA 6000
PRELIMINARY DATA SHEET
Version 2.1
Peripherals
7 - 12 Micronas
The maximum input frequency which is allowed in incremental interface mode is
f
hw_clk
/
8 (BPS = 01). To ensure that a transition of any input signal is correctly recognized, its
level should be held high or low for at least 4
f
hw_clk
cycles (BPS = 01) before it changes.
In Incremental Interface Mode the count direction is automatically derived from the
sequence in which the input signals change, which corresponds to the rotation direction
of the connected sensor.
Table 7-5 summarizes the possible combinations.
The figures below give examples of T3’s operation, visualizing count signal generation
and direction control. It also shows how input jitter is compensated, which might occur if
the sensor rests near to one of its switching points.
Figure 7-7 Evaluation of the Incremental Encoder Signals
Table 7-5 Core Timer T3 (Incremental Interface Mode) Count Direction
Level on
Respective other
Input T3IN Input T3EUD Input
Rising Falling Rising Falling
High Down Up Up Down
Low Up Down Down Up
UET11137
Up Down Up
Forward Jitter Backward Jitter Forward
T3IN
T3EUD
Contents
of T3
Note: This example shows the timer behavior assuming that T3 counts upon any transition on
any input, i.e. T3I = ’011
B
’.