EM357-RTR datasheet(135/240 Pages) ETC2

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EM351 / EM357

Select the active input for TIMx_CCR2by writing the TIM_CC2S bits to 10 in the TIMx_CCMR1 register (TI1

selected).

Select the active polarity for TI1FP2 (used for capture in the TIMx_CCR2) by writing the TIM_CC2P bit to 1

(active on falling edge).

Select the valid trigger input by writing the TIM_TS bits to 101 in the TIMx_SMCR register (TI1FP1

selected).

Configure the slave mode controller in reset mode by writing the TIM_SMS bits to 100 in the TIMx_SMCR

Enable the captures by writing the TIM_CC1E and TIM_CC2E bits to 1 in the TIMx_CCER register.

Figure 9-20 illustrates this example.

Figure 9-20. PWM Input Mode Timing

9.3.7

Forced Output Mode

In output mode (CCyS bits = 00 in the TIMx_CCMR1 register), software can force each output compare signal

(OCyREF and then OCy) to an active or inactive level independently of any comparison between the output

compare register and the counter.

To force an output compare signal (OCyREF/OCy) to its active level, write 101 in the TIM_OCyM bits in the

corresponding TIMx_CCMR1 register. OCyREF is forced high (OCyREF is always active high) and OCy gets the

opposite value to the TIM_CCyP polarity bit. For example, TIM_CCyP = 0 defines OCy as active high, so when

OCyREF is active, OCy is also set to a high level.

The OCyREF signal can be forced low by writing the TIM_OCyM bits to 100 in the TIMx_CCMR1 register.

The comparison between the TIMx_CCRy shadow register and the counter is still performed and allows the

INT_TIMxCCRyIF flag to be set. Interrupt requests can be sent accordingly. This is described in the output

compare mode section.

9.3.8

Output Compare Mode

This mode is used to control an output waveform or to indicate when a period of time has elapsed.

When a match is found between the capture/compare register and the counter, the output compare function:

Assigns the corresponding output pin to a programmable value defined by the output compare mode (the

TIM_OCyM bits in the TIMx_CCMR1 register) and the output polarity (the TIM_CCyP bit in the TIMx_CCER

(TIM_OCyM = 010), or can toggle (TIM_OCyM = 011) on the match.

9-15

120-035X-000D

Preliminary

EM357-RTR 数据表(PDF) 135 Page - List of Unclassifed Manufacturers