User Manual
553
Rev. 1.1
2019-03-18
TLE984xQX
Microcontroller with LIN and Power Switches for Automotive Applications
Capture/Compare Unit 6 (CCU6)
18.7
Hall Sensor Mode
For Brushless DC-Motors in block commutation mode, the Multi-Channel Mode has been introduced to
provide efficient means for switching pattern generation. These patterns need to be output in relation to the
angular position of the motor. For this, usually Hall sensors or Back-EMF sensing are used to determine the
angular rotor position. The CCU6 provides three inputs, CCPOS0, CCPOS1, and CCPOS2, that can be used as
inputs for the Hall sensors or the Back-EMF detection signals.
There is a strong correlation between the motor position and the output modulation pattern. When a certain
position of the motor has been reached, indicated by the sampled Hall sensor inputs (the Hall pattern), the
next, pre-determined Multi-Channel Modulation pattern has to be output. Because of different machine types,
the modulation pattern for driving the motor can vary. Therefore, it is wishful to have a wide flexibility in
defining the correlation between the Hall pattern and the corresponding Modulation pattern. Furthermore, a
hardware mechanism significantly reduces the CPU for block-commutation.
The CCU6 offers the flexibility by having a register containing the currently assumed Hall pattern (CURH), the
next expected Hall pattern (EXPH) and the corresponding output pattern (MCMP). A new Modulation pattern
is output when the sampled Hall inputs match the expected ones (EXPH). To detect the next rotation phase
(segment for block commutation), the CCU6 monitors the Hall inputs for changes. When the next expected
Hall pattern is detected, the next corresponding Modulation pattern is output.
To increase for noise immunity (to a certain extend), the CCU6 offers the possibility to introduce a sampling
delay for the Hall inputs. Some changes of the Hall inputs are not leading to the expected Hall pattern, because
they are only short spikes due to noise. The Hall pattern compare logic compares the Hall inputs to the next
expected pattern and also to the currently assumed pattern to filter out spikes.
For the Hall and Modulation output patterns, a double-register structure is implemented. While register
MCMOUT holds the actually used values, its shadow register MCMOUTS can be loaded by software from a pre-
defined table, holding the appropriate Hall and Modulation patterns for the given motor control.
A transfer from the shadow register into register MCMOUT can take place when a correct Hall pattern change
is detected. Software can then load the next values into register MCMOUTS. It is also possible by software to
force a transfer from MCMOUTS into MCMOUT.
Note:
The Hall input signals CCPOSx and the CURH and EXPH bit fields are arranged in the following order:
CCPOS0 corresponds to CURH.0 (LSB) and EXPH.0 (LSB)
CCPOS1 corresponds to CURH.1 and EXPH.1
CCPOS2 corresponds to CURH.2 (MSB) and EXPH.2 (MSB)