MPC5748 - Using FlexCAN SLFWAK

[jschwartz]

Hello,

I'm trying to use the SLFWAK mechanism in FlexCAN to wake up from STOP mode. I've been unable to get it to function correctly..

My hardware uses the MCP2562 transceiver and the FlexCAN configuration is as follows:

- FD Enabled

- FRZ mode set before STOP mode entry

- WAKMSK and SLFWAK both set

- FlexCAN peripheral clock enabled in STOP mode.

I noticed two things as I've worked on this. The first is that I don't see an interrupt vector for FlexCAN WAKINT, second is that I haven't been able to wake the chip by any means if I have the debugger attached. I'm using GHS MULTI 6.16 and the GHS Probe. This issue is irritating, but I can work around it. My application must be able to wake up on CAN so this is a show-stopper right now.

[PetrS]

Hi,

As far as I know this Self-Wake up feature is not supported on the MPC5748G, thus no interrupt vector is available for that.

However the Pretended Networking mode adds specific wake up functionality in low power modes (STOP and LPU_STOP modes), see chapter 43.5.5. of the Device Reference manual.

The FlexCAN PN is only implemented in FLEXCAN_0 and the interrupt vector is #565 FlexCAN0_0 FlexCAN0_PN //included in Table 23-1. INTC Vector Table.

Beside that you can use the Wake-up module and assign CAN_RX pin as external wakeup source. Thus the edge on  the pin will wake-up the device.For example pin PB1/CAN0RX is mapped to WKUP4 source.

BR, Petr