SNIP_CLASSIC_CANTP_SECTION_7_Functional_specification

7 Functional specification This section provides a description of the CAN Transport Layer functionality. It explains the services provided to the upper and lower layers and the internal behavior of the CAN Transport Layer. The CanTp module offers services for segmentation, transmission with flow control, and reassembly of messages. Its main purpose is to transmit and receive messages that may or may not fit into a single CAN frame. Messages that do not fit into a single CAN frame are segmented into multiple parts, such that each can be transmitted in a single CAN frame. While reading this document, it is necessary to bear in mind, that this module will follow the recommendations ISO 15765-2 (OEM enhanced diagnostics [1]) and should be able to fulfill ISO 15765-4 (Requirements for emissions-related systems [2]). [SWS_CanTp_00033] Upstream requirements: SRS_Can_01065 ⌈If a recommendation of ISO 15765-2 is not explicitly excluded in the SWS, the CanTp module shall follow this recommendation.⌋ For further descriptions of SF, FF, CF and FC frames, network layer timing parameters, and further functionalities of CAN Transport Layer please refer to the ISO 15765-2 specification [1]. ISO 15765-4 is a particular case of ISO-15765-2. Therefore, the CAN Transport Layer will be configurable in order to be able to adapt the module to all ISO 15765-4 use cases (e.g. specific timing, padding configuration, addressing mode). See chapter 10, Configuration specification, for details.