st7pmc2s6 STMicroelectronics, st7pmc2s6 Datasheet - Page 224

• Manufacturer Part Number: st7pmc2s6
• Description: 8-bit Mcu For Automotive With Nested Interrupts, Flash, 10-bit Adc, Brushless Motor Control, 5 Timers, Spi, Linsci?
• Manufacturer: STMicroelectronics

On-chip peripherals
Figure 98. Simulated commutation and Z event
Figure 99
electrical step with the corresponding accuracy on the measure (right axis) as a function of the
mechanical frequency.
For a given prescaler value (step ratio register) the mechanical frequency can vary between two fixed
values shown on the graph as the segment ends. In autoswitched mode, this register is automatically
incremented/decremented when the step frequency goes out of this segment.
At f
(pole pair x rpm) with a minimum accuracy of 1.2% on the step period.
To read the number of samples for Zn within one step (right Y axis), select the mechanical frequency on
the X axis and the sampling frequency curve used for BEMF detection (PWM frequency or measurement
window frequency). For example, for N.Frpm = 15000 and a sampling frequency of 15 kHz, there are
approximately 10 samples in one step and there is a 10% error rate on the measurement.
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MTC
Z
SC bit is reset. The result
of the hardware multiplication
is put in MCOMP-->C
compared with MTIM once
written.
= 4 MHz, the range covered by the step ratio mechanism goes from 2.39 to 235000
gives the step ratio register value (left axis) and the number of BEMF sampling during one
C
H
D
H
and
ST7MC1K2-Auto, ST7MC1K6-Auto, ST7MC2S4-Auto, ST7MC2S6-Auto
SC bit is set during Z IT. The
hardware multiplication is taken into
account but the value in MCOMP can
be overwritten
Z
MCOMP
register
C
s
D
Z
Z
D
C
C
C
H
S
s
Zero-crossing event
Demagnetization event
Hardware commutation
Simulated commutation
SC bit is already set when Z IT occurs.
The hardware multiplication is not
taken into account. A value has to be
written in the MCOMP register.
D
Z
t