AN2515 Freescale Semiconductor / Motorola, AN2515 Datasheet - Page 13

• Manufacturer Part Number: AN2515
• Description: 3-Phase Sine Wave Generator - 3 outputs version TPU Function Set
• Manufacturer: Freescale Semiconductor / Motorola

Synchronization
signal for 3-Phase
Sine Wave
Generator – 3
outputs version
(3Sin3_sync)
MOTOROLA
3-Phase Sine Wave Generator – 3 outputs version TPU Function Set (3Sin3)
When other functions are running concurrently on the same TPU, the longest
state of each function with its time-slot transition can increase the calculated
MPW value. The 3Sin3_fault function does not affect the MPW. The
3Sin3_sync, if used, increases the MPW value by 22 (44 IMB clock cycles). The
3Sin3_res, if used, increases the MPW value by 20 (40 IMB clock cycles).
It is also possible to use the Worst-Case Latency (WCL), which is automatically
calculated by the MPC500_Quick_Start Graphical Configuration Tool. It can
serve as a good approximation of MPW. The calculated WCL is always longer
than the real-case is. Let the WCL be calculated after the configuration of TPU
channels and then find the longest WCL value within all 3Sin3 PWM channels.
Convert the number, from IMB clock cycles to TCR1 clock cycles, to get the
MPW.
The 3Sin3_sync TPU function uses information obtained from 3Sin3 PWM
functions, the actual PWM center times and the PWM periods. This allows a
signal to be generated, which tracks the changes in the PWM period and is
always synchronized with the PWM. The synchronization signal is a positive
pulse generated repeatedly after the prescaler or presc_copy PWM periods
(see next paragraph). The low to high transition of the pulse can be adjusted
by a parameter, either negative or positive, to go a number of TCR1 TPU cycles
before or after the PWM period center time. The pulse width pw is another
synchronization signal parameter.
move > 0
move > 0
prescaler = 1
prescaler = 1
move < 0
move < 0
prescaler = 2
prescaler = 2
Freescale Semiconductor, Inc.
For More Information On This Product,
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Figure 7. Synchronization signal adjustment examples
center_time
center_time
center_time
center_time
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Go to: www.freescale.com
pw
pw
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pw
pw
center_time
center_time
center_time
center_time
center_time
center_time
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Detailed Function Description
center_time
center_time
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AN2515/D
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