I am trying to switch to external crystal oscillator for FlexCAN but after configuring the CLKSRC bit in CTRL1 and negating the MDIS bit for enabling FlexCAN, still LPMACK bit is 1. It seems like FlexCAN is getting stuck in low power mode. Any solution?
Code for configuring EREFS in SOSCCFG:
SCG->SOSCCSR &= ~SCG_SOSCCSR_SOSCEN_MASK;//disabling SOSC
SCG->SOSCDIV =
(
SCG_SOSCDIV_SOSCDIV1(1)
| SCG_SOSCDIV_SOSCDIV2(1)
);
SCG->SOSCCSR &= ~SCG_SOSCCSR_LK_MASK; //unlocking SOSCCSR
SCG->SOSCCFG = SCG_SOSCCFG_RANGE(2) | SCG_SOSCCFG_HGO(0) | SCG_SOSCCFG_EREFS(0); // selecting crystal oscillator
SCG->SOSCCSR |= SCG_SOSCCSR_SOSCEN_MASK; //enabling SOSC
SCG->SOSCCSR |= SCG_SOSCCSR_LK_MASK; //locking SOSCCSR
Code for CLKSRC selection:
CAN0->MCR |= CAN_MCR_MDIS_MASK; /* MDIS=1: Disable module before selecting clock */
CAN0->CTRL1 &= ~CAN_CTRL1_CLKSRC_MASK;
CAN0->MCR &= ~CAN_MCR_MDIS_MASK; /* MDIS=0; Enable module config. (Sets FRZ, HALT)*/
After this code : MDIS=0, LPMACK=1, FRZACK=0
