Infineon TLE984 QX Series, Руководство пользователя

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User Manual 443 Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
General Purpose Timer Units (GPT12)
Figure 91 Connection of the Encoder to the TLE984xQX
For incremental interface operation, the following conditions must be met:
• Bitfield T3M must be 110
B
or 111
B
.
• Both pins T3IN and T3EUD must be configured as input.
• Pin T4IN must be configured as input, if used for T0.
• Bit T3UDE must be 1 to enable automatic external direction control.
The maximum count frequency allowed in Incremental Interface Mode depends on the selected prescaler
value. To ensure that a transition of any input signal is recognized correctly, its level must be held high or low
for a minimum number of module clock cycles before it changes. This information can be found in
Section 16.3.5 .
As in Incremental Interface Mode two input signals with a 90° phase shift are evaluated, their maximum input
frequency can be half the maximum count frequency.
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 238
summarizes the possible combinations.
Figure 92 and Figure 93 give examples of T3’s operation, visualizing count signal generation and direction
control. They also show how input jitter is compensated, which might occur if the sensor rests near to one of
its switching points.
Table 238 GPT1 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
Encoder Controller
A
B
T0
T3Input
T3Input
Interrupt
or T4IN
A
B
B
T0
T0
A
Signal
Conditioning
MC_GPT1_ENCODER