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Different members of the same development board family(NUCLEO-H753ZI & NUCLEO-H743ZI2) require different CAN bit timings?

JKang.3
Associate

I am currently using two development board devices(NUCLEO-H753ZI & NUCLEO-H743ZI2) for CAN communications. Seeing as both are from the same MCU family and have identical board layouts, I assumed configuring the CAN peripherals for both devices would be identical as well. However, I get inconsistent results when using CAN on both devices. On the NUCLEO-H753ZI, the CAN comms work as intended, on the NUCLEO-H743ZI2, the CAN comms show slight bit timing errors. Is there something I'm missing here when configuring the CAN peripherals between these two devices? The same issue applies with the development boards that use the same MCUs (H753ZI in this case).

1 REPLY 1

The ST-LINK/V3 doesn't generate a nice 8 MHz HSE clock, it's configurable, but generally 25/3 MHz (so 8.3333 MHz)

The ST-LINK/V2 generated a crystal sourced 8 MHz

The timing performance / quality on these platforms will thus be quite different.

Get a better timing source, or tune the PLL settings so the frequency you're running the H7 at is established more accurately, perhaps change HSE_VALUE too.

You can populate the HSE crystal on the H7 side. Perhaps look if you can steal the clock from the Ethernet implementation via a trace wire.

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