I am trying to bring up a new board and am running into a problem initializing the CAN bus.
Part: STM32L4Q5CGT6P
CAN baud rate 500kbps
Can Transceiver is being used.
I first found this problem with custom code but it is probably easier to describe relating to cube / Hal code that has the same results.
Using the standard Cube/Hal code for this part the first sign of a problem is that it fails on CAN_init
The following code will always hit the error handler
CanHandle.Instance = CANx;
CanHandle.Init.TimeTriggeredMode = DISABLE;
CanHandle.Init.AutoBusOff = DISABLE;
CanHandle.Init.AutoWakeUp = DISABLE;
CanHandle.Init.AutoRetransmission = ENABLE;
CanHandle.Init.ReceiveFifoLocked = DISABLE;
CanHandle.Init.TransmitFifoPriority = DISABLE;
CanHandle.Init.Mode = CAN_MODE_NORMAL;
CanHandle.Init.SyncJumpWidth = CAN_SJW_1TQ;
CanHandle.Init.TimeSeg1 = CAN_BS1_5TQ;
CanHandle.Init.TimeSeg2 = CAN_BS2_2TQ;
CanHandle.Init.Prescaler = 15;
if (HAL_CAN_Init(&CanHandle) != HAL_OK)
{
/* Initialization Error */
Error_Handler();
}
Monitoring the registers involved I have noticed the following.
MSR->Reset never clears the reset bit
Using cube code it will not leave sleep
If I clear sleep in MCR and Set INRQ I can get it to move from sleep to Initializing (MSR->INAK) but it will never leave INAK.
To eliminate problems I removed the CAN transceiver and installed a 3.3k pull up to 3.3v with a diode to tx joining the RX and TX pins together. This had no effect on the problems above.
I have also tried the "Can_Networking" example from Cube L4 ported over to this part and still receive the same errors.
Has anyone seen this before? I am hoping there is some register or peripheral power I am missing somewhere in the process.
