EM357-RTR datasheet(132/241 Pages) SILABS

Nome de Peças	EM357-RTR

Descrição Electrónicos	High-Performance, Integrated ZigBee/802.15.4 System-on-Chip

PDF	241 Pages

Scroll/Zoom	100%

Fabricante Electrônico	SILABS [Silicon Laboratories]

Página de início	http://www.silabs.com

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132 / 241 page

Rev 1.3

132

Figure 9.23. Center-Aligned PWM Waveforms (ARR = 8)

Hints on using center-aligned mode:



When starting in center-aligned mode, the current up-down configuration is used. This means that the

counter counts up or down depending on the value written in the TIM_DIR bit in the TIMx_CR1 register.

The TIM_DIR and TIM_CMS bits must not be changed at the same time by the software.



Writing to the counter while running in center-aligned mode is not recommended as it can lead to

unexpected results. In particular:



The direction is not updated when the value written to the counter that is greater than the auto-reload value

(TIMx_CNT > TIMx_ARR). For example, if the counter was counting up, it continues to count up.



The direction is updated when 0 or the TIMx_ARR value is written to the counter, but no UEV is generated.



The safest way to use center-aligned mode is to generate an update by software (setting the TIM_UG bit in

the TIMx_EGR register) just before starting the counter, and not to write the counter while it is running.

EM357-RTR Folha de dados(PDF) 132 Page - Silicon Laboratories