AN2367 Freescale Semiconductor / Motorola, AN2367 Datasheet - Page 8

• Manufacturer Part Number: AN2367
• Description: Using the Multiphase Motor Commutation TPU Function (COMM)with the MPC500 Family
• Manufacturer: Freescale Semiconductor / Motorola

COMM Routines
2.4.4
This function sets the upper angular boundary of the current commutation state. After the CPU has
completed forcing states during the motor start-up sequence, upper should be written to an appropriate value
based on the position count value and the current state length. After this has been done the TPU will
automatically update the upper angular boundary value each time a state transition occurs. The function has
three parameters.
2.4.5
This function sets the lower angular boundary of the current commutation state. After the CPU has
completed forcing states during the motor start-up sequence, lower should be written to an appropriate value
based on the position count value and the current state length. After this has been done the TPU will
automatically update the lower angular boundary value each time a state transition occurs. The function has
three parameters.
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channel – This is the channel selected as the master channel for the COMM function. The number
of pins required for commutation determines the number of channels used by COMM. The
additional required channels are adjacent to, and follow, the master channel in the TPU.
no_of pins - This parameter determines the number of channels to be used to generate the
commutation signals (including the master channel). The maximum number of channels that can
be used is eight. To set up the COMM function for three-phase commutation, using six channels,
no_of_pins should be 0x06.
counter_addr – This parameter is used to indicate the address in parameter RAM of the angular
position counter that is used as the basis of the state tests in sensorless mode. For example, if
COMM is used in conjunction with FQD, and channel 4 is used as the master channel for FQD,
then counter_addr would be set to 0x0042 to select POSITION_COUNT in FQD’s parameter
RAM as the angular position counter.
update_period – In sensorless mode this parameter determines the frequency of update (in TCR1
counts) of the commutation signals. It is used to schedule a periodic match on the master channel.
comm_states[] – This is an array of values containing the LENGTH and PIN CONFIG values for
each commutation state. LENGTH comprises the upper eight bits of an array element and defines
the length (in position counter increments) of each state. PIN CONFIG comprises the lower eight
bits of an array element. This is right justified. If six pins are used for commutation, the lower six
bits of the field are used to hold the pin values. A logic one in the PIN CONFIG field will result in
the corresponding pin being driven low, and a logic zero will result in the pin being driven high.
no_of_states – This parameter indicates the number of states used in the commutation sequence.
*tpu – This is a pointer to the TPU3 module to be used. It is of type TPU3_tag, which is defined in
m_tpu3.h
channel – This is the channel selected as the master channel for the COMM function.
upper – This value contains the value of the upper angular boundary of the current commutation
state (in position counts).
*tpu – This is a pointer to the TPU3 module to be used. It is of type TPU3_tag, which is defined in
m_tpu3.h
channel – This is the channel selected as the master channel for the COMM function.
void tpu_comm_write_upper )
void tpu_comm_write_lower
Using the Multiphase Motor Commutation TPU Function
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