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MCU Peripherals
2.6 Overcurrent level
The overcurrent signal is connected via the TWR-Elevator IRQ_A (B62) pin to the GPIO_B2 pin of the MKV10Z32 device.
This pin is internally connected to the FTM0_FLT1 signal that handles the fault by PWM hardware. See Figure 3.
The overcurrent level can be set in the range of 0~8 A by the trimmer R37 on the TWR-MC-LV3PH board. The maximum
current level can be set by turning the trimmer counterclockwise. The user can find the level by turning the trimmer
counterclockwise while the motor is running until the red LED is lit. It is recommended to set the trimmer to a somewhat
higher level, so that the motor can operate at maximum speed.
Figure 3. Overcurrent level
2.7 SPI configuration
The SPI interface is used in the application for communication between the intelligent MOSFET gate driver MC33937 and
the KV10 MCU. The MC33937 gate driver is placed on the Tower System low-voltage power module and serves for driving
the high-side and low-side MOSFET transistors of the three-phase inverter. In the application, the initialization of the
MC33937 must be performed, primarily to set dead time. During the motor operation there is also periodic checking of the
status register of the driver, to provide information on the latched faults. The MC33937 driver requires precise timing of the
SPI signals. The default setting of the SPI module on the MCU is not possible to use. The exact timing of the SPI signals is
listed in [5].
2.8 SCI (UART) configuration
The SCI is used in the application for the communication between the master system and the embedded application. A master
system is the notebook or the PC where the FreeMASTER software is installed to control the application and visualization of
its state. On the Kinetis KV10, there are two UART modules implemented. Because the hardware solution is based on the
Tower System development boards, the UART1 is used. The communication speed is set to 19200 Bd and is limited by use
of the OpenSDA - CDC serial communication driver. The use of direct RS232 connection between the PC and the embedded
side enables an increase of the communication speed to 115200 Bd.
Three-Phase PMSM Sensorless FOC Using the MKV10Z32 with Automated Motor Parameters
Identification, Rev. 0, 12/2014
Freescale Semiconductor, Inc.
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