SNIP_CLASSIC_PLATFORM_SECTION_4_3_On_Wire_Representation

4.3 On Wire Representation [RS_SOMEIP_00027] SOME/IP protocol shall define the header layout of messages Upstream requirements: RS_Main_00280 ⌈ Description: SOME/IP protocol shall define the header layout of messages for a respective version. Rationale: The layout of the header needs to be understood by the communication partners. Use Case: Communication between different parties. AppliesTo: FO Dependencies: – Supporting Material: – ⌋ [RS_SOMEIP_00028] SOME/IP protocol shall specify the serialization algorithm for data Upstream requirements: RS_Main_00280 ⌈ Description: SOME/IP protocol shall specify the serialization algorithm for data to convert the machine-specific memory representation to a common network-representation. Rationale: The memory representation of data heavily depends on processor architecture and compiler settings which differ between the machine in the vehicle. Use Case: Communication of payload between communication partners using different processor architectures. AppliesTo: FO Dependencies: – Supporting Material: – ⌋ [RS_SOMEIP_00029] SOME/IP protocol shall specify how data in the payload are aligned Upstream requirements: RS_Main_00280 ⌈ Description: SOME/IP protocol shall specify how data in the payload are aligned. This includes the start of primitive data types and gaps between them. Rationale: Some architectures allow a faster access to data which are aligned in memory. If speed matters, it is useful to be able to influence the alignment and optimize the accesses. Use Case: Fast access to serialized representation of structured data types. AppliesTo: FO Dependencies: – Supporting Material: – ⌋ [RS_SOMEIP_00026] SOME/IP protocol shall define the endianness of header and payload Upstream requirements: RS_Main_00280 ⌈ Description: SOME/IP protocol shall define the endianness of data representation in header and payload. The communication partners shall use that endianness on the network. Rationale: If machines with different endianness communicate with each other, the format on the network needs to be defined. Use Case: A little-endian machine communicates with a big-endian machine. AppliesTo: FO Dependencies: – Supporting Material: – ⌋ [RS_SOMEIP_00030] SOME/IP protocol shall support transporting integer data types Upstream requirements: RS_Main_00280 ⌈ Description: SOME/IP protocol shall support transporting integer data types, signed and unsigned of 8, 16 and 32 bit length. Rationale: For the specification of a serialization algorithm of SOME/IP, a set of basic data types needs to be supported by SOME/IP. Use Case: Communication of c-data types AppliesTo: FO Dependencies: – Supporting Material: – ⌋ [RS_SOMEIP_00031] SOME/IP protocol shall support transporting boolean data type Upstream requirements: RS_Main_00280 ⌈ Description: SOME/IP protocol shall support transporting boolean data type. Rationale: For the specification of a serialization algorithm of SOME/IP, a set of basic data types needs to be supported by SOME/IP. Use Case: Communication of boolean values. AppliesTo: FO Dependencies: – Supporting Material: – ⌋ [RS_SOMEIP_00032] SOME/IP protocol shall support transporting float data types Upstream requirements: RS_Main_00280 ⌈ Description: SOME/IP protocol shall support transporting float data types kown as single and double (defined in IEEE 754 [3] as binary32 and binary64) Rationale: For the specification of a serialization algorithm of SOME/IP, a set of basic data types needs to be supported by SOME/IP. Use Case: Communication of c-data types ▽ △ AppliesTo: FO Dependencies: – Supporting Material: – ⌋ [RS_SOMEIP_00033] SOME/IP protocol shall support transporting structured data types Upstream requirements: RS_Main_00280 ⌈ Description: SOME/IP protocol shall support transporting structured data types which can consist of one or multiple structured data types of fixed or variable size and/or primitive data types. Rationale: For the specification of a serialization algorithm of SOME/IP, a set of data types needs to be supported by SOME/IP. Use Case: Consistent communication of more than one primitive data type. AppliesTo: FO Dependencies: – Supporting Material: – ⌋ [RS_SOMEIP_00034] SOME/IP protocol shall support transporting union data types Upstream requirements: RS_Main_00280 ⌈ Description: SOME/IP protocol shall support transporting union data types where the concrete data type is determined during execution. Rationale: For the specification of a serialization algorithm of SOME/IP, a set of data types needs to be supported by SOME/IP. Use Case: Communication of data with the possibility to choose representation dynamically. AppliesTo: FO Dependencies: – Supporting Material: – ⌋