topic Re: How do I setup Flexcan fifo on k64? in Kinetis Microcontrollers

How do I setup Flexcan fifo on k64?

ahmedsobhy — Sun, 04 Mar 2018 23:59:12 GMT

I have the Flexcan module on the K64 setup to receive data from the CAN bus using Message Buffers. I setup each Message buffer with a specific ID to listen to and receive the info from the bus.

Everytime a message is received the module causes an Interrupt. I then read the data from the message buffer and so on. I would like to know if there is a better implementation using FIFO buffers for example, that would not cause any messages to be dropped and at the same time reduce the workload on the MCU.

Thank you,

Ahmed.

Re: How do I setup Flexcan fifo on k64?

miduo — Fri, 09 Mar 2018 08:42:38 GMT

Hi,

Please make reference from the FlexCAN project that was released for the Kinetis K6X. You can find the project in the KINETIS_SC.zip file on NXP website. There is a "can_loopback_node" project included that has example CAN driver code. Thre is an ISR that can handle transmit included. The FlexCAN_Poll_TxMBs() function in the can.c file is probably of the most interest to you. The function references polling, but it is called by the MB isr function.

Re: How do I setup Flexcan fifo on k64?

ahmedsobhy — Fri, 09 Mar 2018 18:05:48 GMT

Thank you Fang. I am using one of the example projects actually as a template. What I am interested in is the receiving not transmitting. I have made some modification to my code since that time is that I setup several MBs on the flexcan module to the IDs I want to recieve on the bus, then since I know that the message are gonna be sent as a burst and in order I interrupt only once when the last message is received and this is how I reduce the number of times the MCU has to context switch to run the interrupt and store then data.