AN1914 Freescale Semiconductor / Motorola, AN1914 Datasheet - Page 45

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

7.3.6 State Diagram - Process Current PI Controller
7.3.7 State Diagram - Process Fault Control
7.3.7.1 PWM Fault A Interrupt Subroutine
Current Control
The Current PI controller algorithm controllerPItype1 is described in the SDK documentation. The
controller execution (sampling) period is determined by the PWM module period, because the ADC
conversion is started each PWM reload (once per PWM period). The Current Control Request is set in
ADC Conversion Complete Interrupt.
The process Fault State is described by Interrupt subroutines which provide its functionality.
This subroutine is called at PWM A (or PWM in case of DSP56F803) Fault Interrupt.
In this interrupt subroutine following faults from PWM Fault pins are processed:
Request
•
•
PI (Reference Current - Actual Current)
when Overvoltage occurs (the Overvoltage fault pin set)
— DriveFaultStatus |= OVERVOLTAGE
when Overcurrent occurs (the Overcurrent fault pin set)
— DriveFaultStatus |= OVERCURRENT
Figure 7-10. State Diagram - Process Speed PI Controller
DSP56F80x MC PWM Module in Motor Control Applications
U_Desired =
Conversions
Start ADC
Freescale Semiconductor, Inc.
For More Information On This Product,
(PWM period)
PWM Reload
Interrupt
Go to: www.freescale.com
Stopped/Starting/Running
Commutation Status
Alignment
Commutation
Set Current Control
Request
Complete Interrupt
ADC Conversion
Current Control
(PWM period)
Disabled
Reset
SW Design
45