This application note describes the CAN Protocol, Siemens CAN devices and different options for connecting devices of the Siemens C166 and C500 microcontroller families to the Controller Area Network (CAN). Abbreviations and Symbols3 1 Introduction...........4 2 The Controller Area Network (CAN) 6 2.1 CAN Basics .........6 2.2 Addressing and Bus Arbitration.......7 2.3 The different CAN Frames and their Formats 8 2.4 The Nominal Bit Time......14 2.5 Error Detection and Error Handling15 2.6 The different CAN Implementations .16 3 The Siemens CAN Devices C167CR, C515C and SAE 81C90/91.18 3.1 The Microcontroller Families C500 and C166 at a Glance ...........18 3.2 The CAN Module on the C167CR / C515C ..19 3.3 The Stand-Alone Full-CAN Controller SAE 81C90/91 ....26 4 Examples for the Connection of Siemens Microcontrollers to CAN ........29 4.1 Connecting the C167CR / C515C to CAN....29 4.2 Connecting the SAB 80C166 to CAN via the SAE 81C90.30 4.3 Connecting the C511 / C513 to CAN via the SAE 81C91 .32 4.4 A Proposal for the CAN Bus Cables.33 5 Ways of Handling the SAE 81C90/91 and the CAN Module on the C167CR / C515C ....34 5.1 Notes on the following Sections ....34 5.2 Accessing the Registers of the CAN Module / the SAE 81C90/9134 5.3 Configuration of the Bit Timing......37 5.4 Ways of Handling the CAN Module41 5.5 Ways of Handling the SAE 81C90/91 ..........55 5.6 How to use the Basic CAN Features 61