Patent ID: 11934338
Assignee: RENESAS ELECTRONICS AMERICA INC.
Field: Digital communication (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 6:
7. A controller area network (CAN) controller for securely receiving CAN protocol frames, the CAN controller configured to:
receive a frame transmitted from a receiver;
extract a CAN identification (ID), a freshness value, a payload, and an integrity check value (ICV) from the received frame;
determine a freshness of the received frame based on the extracted freshness value and an acceptable freshness that corresponds to a maximum difference between the extracted freshness value and an expected freshness value;
determine an authenticity of the received frame by comparing a generated ICV to the extracted ICV, and in response to the freshness of the received frame within the acceptable freshness window;
determine to set a receive flag in response to the generated ICV matching the extracted ICV; determine to store the extracted freshness value in a first CAN controller register, based on the determining the freshness and the determining the authenticity of the frame; and
overwriting a previous freshness value with the extracted freshness value based on the extracted CAN ID.