AN1914 Freescale Semiconductor / Motorola, AN1914 Datasheet - Page 40

• Manufacturer Part Number: AN1914
• Description: 3-Phase BLDC Motor Control with Sensorless Back EMF Zero Crossing Detection Using DSP56F80x
• Manufacturer: Freescale Semiconductor / Motorola

SW Design
7.3.4 State Diagram - Process Commutation Control
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Reset
Drive Fault
In manual control, the application is controlled with Start/Stop switch and Up Down Push buttons to
set Required Speed.
In PC Master control mode the Start/Stop is controlled manually and the Required Speed is set via the
PC Master.
The motor is stopped whenever the absolute value of Required speed is lower then Minimal Speed or
switch set to stop or if there is a system failure - Drive Fault (Emergency Stop) state is entered. All the
SW processes are controlled according this Application State Machine status.
State Diagram of the process Commutation Control is shown in
process takes care of the sensorless BLDC motor commutation. The requirement to run the BLDC
motor is determined by upper software level Application State Machine. When the Application State
Machine is in BLDC Stop state, Commutation Control status is Stopped. If it is in BLDC Stop state,
the Commutation Control goes through the states described in section
following possible states:
•
Alignment state
Figure 7-6. State Diagram - Process Application State Machine
Bldc Stop
Required Speed
Up Button
(Switch = Stop) || (abs (Required Speed) <= Minimal Speed)
Increment
DSP56F80x MC PWM Module in Motor Control Applications
(Switch = Run) & (abs (Required Speed) > Minimal Speed)
Freescale Semiconductor, Inc.
Emergency Stop
For More Information On This Product,
Drive Fault
Go to: www.freescale.com
Down Button
Required Speed
Decrement
with Required Speed
Figure
Bldc Run
Required Speed setting
7-7. The Commutation Control
Required Speed
Section
PC Master
Set
Drive Fault
5. So there are the