AN2528 Freescale Semiconductor / Motorola, AN2528 Datasheet - Page 4

• Manufacturer Part Number: AN2528
• Description: Standard Space Vector Modulation TPU Function Set
• Manufacturer: Freescale Semiconductor / Motorola

AN2528/D
Detailed Function Description
Standard Space
Vector Modulation –
Top (svmStd_top)
and Standard Space
Vector Modulation –
Bottom
(svmStd_bottom)
4
NOTE:
Standard Space Vector Modulation TPU Function Set (svmStd)
A CPU routine that configures the TPU can be generated automatically using
the MPC500_Quick_Start Graphical Configuration Tool.
The svmStd_top and svmStd_bottom TPU functions work together to generate
a 6-channel, 3-phase PWM signal, with dead-time between the top and bottom
channels. In order to charge the bootstrap transistors, the PWM signals start to
run 1.6ms after their initialization (at 20MHz TCR1 clock). The functions
generate signals corresponding to Reference Voltage Vector Amplitude of 0
(50% duty-cycle) until the first reload values are processed.
The CPU controls the PWM output by setting the TPU parameters. The Stator
Reference Voltage Vector components u
run time. The PWM period T and the prescaler – the number of PWM periods
per reload of new values – are also read at each reload, so these parameters
can be changed during run time. Conversely, dead-time (DT) and minimum
pulse width (MPW) are not supposed to be changed during run time. The CPU
notifies the TPU that the new reload values are prepared by setting the LD_OK
parameter. The TPU notifies the CPU that the reload values have been read
and new values can be written by clearing the LD_OK parameter.
The TPU writes the parameter Sector, which indicates the current Stator
Reference Voltage Vector position in sector 1 to 6.
3. Initializes function parameters. The parameters T, prescaler, DT, MPW,
4. Issues an HSR (Host Service Request) type %10 to one of the
5. Enables servicing by assigning high, middle or low priority to the channel
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SQRT3 and sync_presc_addr must be set before initialization. If an
svmStd_sync channel or an svmStd_res channel is used, then also its
parameters must be set before initialization.
svmStd_bottom channels to initialize all PWM channels. Issues an HSR
type %10 to the svmStd_sync channels, svmStd_res channels and
svmStd_fault channel, if used.
priority bits. All PWM channels must be assigned the same priority to
ensure correct operation. The CPU must ensure that the svmStd_sync
or svmStd_res channels are initialized after the initialization of PWM
channels:
–
–
–
assign a priority to the PWM channels to enable their initialization
if a Synchronization Signal or a Resolver Reference Signal channel
is used, wait until the HSR bits are cleared to indicate that
initialization of the PWM channels has completed and
assign a priority to the svmStd_sync or svmStd_res channels to
enable their initialization
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MOTOROLA