Solution:

The detailed descriptions about acceptance code and acceptance mask are shown as follows: Acceptance mask => 8 bits value 1 : don't care, this bit position is "don't care" for the acceptance of a message, that is to say, if this bit is 1, the corresponding bit of acceptance filter will be disabled. value 0 : the corresponding bit of acceptance filter will be enabled, the message in the CAN bus which fits the corresponding bit of acceptance code will be received. Acceptance code => 8 bits, specifies the value of the 8 most significant bits of the identifier ( ID10 ... ID3 ). If Acceptance mask is 00000000, then the corresponding bits of the identifier must be the same with acceptance code so that this message will be received. Example1: acceptance mask 1111 1111 ( don't care ), acceptance code xxxx xxxx => any message will be received Example2: acceptance mask 0000 0000 ( compare with acceptance code ), acceptance code 1010 1010 => any message with the identifier ( ID10 ... ID3 ) 1010 1010 will be received Example3: acceptance mask 1111 0000, acceptance code xxxx 1111 => any message with the identifier ( ID10 ... ID3 ) xxxx 1111 will be received Note: We sometimes use acceptance mask and acceptance code to filter the messages in the CAN bus.