A CAN Physical Layer Discussion:Many network protocols are described using the seven
layer Open System Interconnection (OSI) model, as shown in Figure 1. The Controller Area Network (CAN) protocol defines the Data Link Layer and part of the Physical Layer in the OSI model. The remaining physical layer (and all of the higher layers) are not defined by the CAN specification. These other layers can either be defined by the system designer, or they can be implemented using existing non-proprietary Higher Layer Protocols (HLPs) and physical layers.The Data Link Layer is defined by the CAN specification.
The Logical Link Control (LLC) manages the overload control and notification, message filtering and recovery management functions. The Medium Access Control (MAC) performs the data encapsulation/decapsulation,error detection and control, bit stuffing/destuffing and the serialization and deserialization functions.