Hi Tommaso,
Please read the KE06 reference manual carefully about the MSCAN filter.
http://www.nxp.com/files/microcontrollers/doc/ref_manual/MKE06P80M48SF0RM.pdf?fasp=1&WT_TYPE=Referen...
page 638, take 32bit maskable identifier as an example:



Standard ID is 11bit, it is from IDAR1 bit 5 to bit7, and IDAR0 bit0-bit7.
So, if you want to just receive the standard ID 0X29, you need to configure it like this:
CAN_IDAR0 : 0x29<<21
IDAR0 | IDAR1 | IDAR2 | IDAR3 |
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
CAN_IDMR0 : 0X001FFFFF
IDMR0 | IDMR1 | IDMR2 | IDMR3 |
7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 1 |
Besides, take care,

1, is igore in filter register
0, is checking.
So, if you want to just get 0X29 standard ID, you must check every standard ID bit.
ID : 0x29<<21 =0X05200000
FILTER : 0X001FFFFF
Wish it helps you!
Have a great day,
Kerry
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