Software Implementation - Motorola M68HC08 Manual

6.1.6 Fault Protection

6.2 Software Implementation

DRM046 — Rev 0
MOTOROLA
Freescale Semiconductor, Inc.
This process is responsible for fault handling. The software
accommodates two fault inputs: DC-Bus over-current signal and DC-Bus
voltage measurement.
DC-Bus over-current is detected by on-board hardware circuitry. In the
case of an over-current, the external hardware provides a falling edge on
the /IRQ input of the microcontroller. This signal invokes a non-masked
interrupt with highest priority. The interrupt service routine puts all PWM
gate signals into a non-active safe state, and sets the fault status of the
drive.
DC-Bus voltage is used for software under-voltage and over-voltage
protection. The sensed DC-Bus voltage is compared with the limit within
the software. In the case of a detected fault, the service routine puts all
PWM gate signals into a non-active safe state, and sets the fault status
of the drive.
If any of the faults occurs the service routine puts the drive into a safe
fault state that does not enable the drive operation. It can be left by
turning the run/stop switch to the stop position.
The general software implementation is illustrated in
6-3. Software Implementation - General
main routine entered from Reset and three interrupt states. The Main
Routine includes the initialization of the microcontroller and the
application, and a Software Timer for the control algorithm time base.
The interrupt states provides calculation of actual speed of the motor,
fault handler and PWM generation process with motor commutation.
Software Design
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Software Design
Software Implementation
Figure
Overview. It incorporates the
Designer Reference Manual
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