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GENERATING A HIGH RESOLUTION SINEWAVE USING ST7 PWMART

Figure 4. PWMART timer initialization

3.3 PWMART INTERRUPT SERVICE ROUTINE

This is the interrupt service routine for the PWMART interrupt. Every time an overflow occurs,

an interrupt is generated (because overflow interrupt is enabled). The PWMART duty cycle is

changed after every “COUNTER” number of overflow cycles. The duty cycle can vary from

~99% to ~1% depending on the sinewave sample values.

AR_TIMER_Init

Start the PWM timer counter, force

counter reload is ON & overflow interrupt

is enabled

Enable PWM0 and con-

figure the polarity

return

Set the frequency of PWMART

by initializing the ARTARR

Initialize the duty cycle

of sinewave to 50%