st7pmc2s6 STMicroelectronics, st7pmc2s6 Datasheet - Page 214

• 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
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In switched mode the user must process the step duration and commutation time by
software.
In autoswitched mode the commutation action is performed automatically depending on the
rotor position information and register contents. This is called the hardware commutation
event C
simulated by writing a value directly in the MCOMP register that is compared with the MTIM
value. This is called simulated commutation C
events on page
Both in switched mode and autoswitched mode, if the SC bit in the MCRC register is set
(software commutation enabled), no comparison between
the MCOMP and MTIM register is enabled before a write access in the MCOMP register.
This means that if the SC bit is set and no write access is done after in the MCOMP register,
no C
In speed measurement mode, when using encoder or tachogenerator speed sensors (that
is, both TES[1:0] bits in the MPAR register are not reset and the input detection block is set-
up to process sensor signals), motor speed can be measured but it is not possible drive a
motor in six-step mode, either sensored or sensorless.
Speed measurement mode is useful for motors supplied with 3-phase sinewave-modulated
PWM signals:
This mode uses only part of the delay manager’s resources. For more details refer to
measurement mode on page
Table 95.
Switched mode
This feature allows the motor to be run step-by-step. This is useful when the rotor speed is
still too low to generate a BEMF. It can also run other kinds of motor without BEMF
generation such as induction motors or switch reluctance motors. This mode can also be
used for autoswitching with all computation for the next commutation time done by software
(hardware multiplier not used) and using the powerful interrupt set of the peripheral.
In this mode, the step time is directly written by software in the commutation compare
register MCOMP. When the MTIM timer reaches this value a commutation occurs (C event)
and the MTIM timer is reset.
At this time all registers with a preload function are loaded (see
registers on page
set an interrupt is generated.
The MTIM timer prescaler (step ratio bits ST[3:0] in the MPRSR register) is user
programmable. Access to this register is not allowed while the MTIM timer is running
(access is possible only before the starting the timer by means of the CKE bit) but the
SWA bit
S
AC induction motors,
Permanent magnet AC (PMAC) motors (although it needs three position sensors, they
can be handled just like tachogenerator signals).
commutation event occurs.
0
1
H
. When enabled by the SC bit in the MCRC register, commutation can also be
Switched and autoswitched modes
221).
ST7MC1K2-Auto, ST7MC1K6-Auto, ST7MC2S4-Auto, ST7MC2S6-Auto
260). The CI bit of MISR is set and if the CIM bit in the MIMR register is
Commutation type
Autoswitched mode
Switched mode
227.
S
(Built-in checks and controls for simulated
MCOMP user access
Section 10.6.13: MTC
Read/Write
Speed