AN2518 Freescale Semiconductor / Motorola, AN2518 Datasheet - Page 18

• Manufacturer Part Number: AN2518
• Description: 3-Phase Sine Wave Generator - 3 outputs version - XOR version TPU Function Set
• Manufacturer: Freescale Semiconductor / Motorola

AN2518/D
Resolver Reference
Signal for 3-Phase
Sine Wave
Generator – 3
outputs version –
XOR version
(3Sin3Xor_res)
Synchronized Change
of PWM Prescaler
And Resolver
Reference Signals
Prescaler
18
3-Phase Sine Wave Generator – 3 outputs version – XOR version TPU Function Set (3Sin3Xor)
The 3Sin3Xor_res TPU function uses information read from the 3Sin3Xor_R
and 3Sin3Xor_T functions, the actual PWM center times and the PWM periods.
This allows a signal to be generated, which tracks the changes of the PWM
period and is always synchronized with the PWM. The resolver reference
signal is a 50% duty-cycle signal with a period equal to prescaler or
synchronization channel 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 3Sin3Xor_res TPU function can inherit the Synchronization Signal
prescaler that is synchronously changed with the PWM prescaler. Write the
synchronization signals presc_copy parameter address to the presc_addr
parameter to enable this mechanism. Write 0 to disable it, and in this case set
the prescaler parameter to directly specify prescaler value.
move > 0
prescaler = 1
move < 0
prescaler = 2
Freescale Semiconductor, Inc.
For More Information On This Product,
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Figure 9. Resolver reference signal adjustment examples
center_time
center_time
T
T
Go to: www.freescale.com
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center_time
center_time
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