AN1905 ST Microelectronics, Inc., AN1905 Datasheet - Page 41

• Manufacturer Part Number: AN1905
• Description: St7mc Three-phase BLDC Motor Control Software Library
• Manufacturer: ST Microelectronics, Inc.

Figure 18. Commutation event processing (Sensorless mode only) continued
Figure 19. Demagnetisation event processing (Sensorless mode only)
SoftDemagTime = 1.25 x (MDREG-MCOMP)
MDREG =
RM event?
no
SENSORLESS
delay_counter <= MAX_DELAY_COUNTER?
yes
SoftDemagTime + MCOMP
MWGHT = RISING/FALLING delay
no
SDM bit set? (hard + soft demag ongoing?)
ST7MC THREE-PHASE BLDC MOTOR CONTROL SOFTWARE LIBRARY
yes
yes
no
MCOMP+SoftDemagTime / 2^(RP_counter) > 0xff ?
SoftDemagTime = SoftDemagTime*2
HSW DEMAG
Adjust SoftDemagTime & RPICounter
for correct MTIM timer overflow
Autoswitchmode?
Return from interrupt
yes
yes
delay_counter = AUTO_DELAY_STEP?
cycle has been forced during demag
SoftDemagTime = 1.25 x MDREG
Restore MCPUHL values if duty
Increase delay_counter
C_IT_AutoSW
HSW DEMAG
no
no
no
Return from interrupt
yes
Update MDREG with user settings
MDREG = preset demag time
Voltage mode?
SW DEMAG
yes
MWGHT = MEDIUM_DELAY
no
C_IT_AutoSW
SW DEMAG
HW DEMAG
D interrupt request?
HW DEMAG
C_IT_AutoSW
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