/* Enables or disables the TIM Capture Compare Channel xN.  */
void TIM_CCxNCmd(TIM_TypeDef *tim, TIMCHx_Typedef channel, TIMCCxNE_Typedef ccxn_en)
/* Enables or disables the TIM Capture Compare Channel xN.  */
void TIM_CCxNCmd(TIM_TypeDef *tim, TIMCHx_Typedef channel, TIMCCxNE_Typedef ccxn_en)
{
    if (channel != TIM_Channel_4)
        MODIFY_REG(tim->CCER, TIM_CCER_CC1NEN << channel, ccxn_en << channel);
}