Rainbow Electronics W90N745CDG - Manual (Page 363)

W90N745CD/W90N745CDG
Publication Release Date: September 22, 2006
- 359 - Revision A2
6.16.1 PWM Double Buffering and Reload Automatically
W90N745 PWM Timers have a double buffering function, enabling the reload value changed for next
timer operation without stopping current timer operation. Although new timer value is set, current timer
operation still operate successfully.
The counter value can be written into PWM_CNR0, PWM_CNR1, PWM_CNR2, PWM_CNR3 and
current counter value can be read from PWM_PDR0, PWM_PDR1, PWM_PDR2, PWM_PDR3.
The auto-reload operation copies from PWM_CNR0, PWM_CNR1, PWM_CNR2, PWM_CNR3 to
down-counter when down-counter reaches zero. If PWM_CNR0~3 are set as zero, counter will be halt
when counter count to zero. If auto-reload bit is set as zero, counter will be stopped immediately.
6.16.2 Modulate Duty Ratio
The double buffering function allows CMR written at any point in current cycle. The loaded value will
take effect from next cycle.