Then, I checked the pin definition against the circuit schematic, and the pin was correctly configured.
Then, look at the chip pin is not faulty solder.
Then, take the oscilloscope probe against the chip's CAN input and output feet, the waveform is quite messy, and the high and low level time is not right, 250k baud rate is not about 4 nanoseconds? How come 25 nanoseconds?
Then, look at the can baud rate configuration, completely ok ah, IPU input, AF_OP output, clock is also on.
Replace another board with the same patch and try the same problem, the board is toxic?
Then, take a closer look at the pcb of the board, and sure enough, the colleague? The board was drawn wrong, the capacitive ground of the crystal oscillator was not connected,......
summarize
Hardware check, whether the main chip and can chip pin are welded, whether the capacitor resistance is welded correctly.
Software check, pin definition, baud rate configuration, filter configuration.