Chart Architecture

hisf_0004: Protect against recursive function calls to improve code compliance

ID: Title	hisf_0004: Protect against recursive function calls to improve code compliance
Description	To improve compliance of generated code, do not call functions recursively. This includes any combination of graphical functions, truth table functions, MATLAB® functions, or Simulink® functions.
Prerequisites	hisf_0011: Stateflow debugging settings hisl_0311: Configuration Parameters > Diagnostics > Stateflow hisl_0060: Configuration parameters that improve MISRA C:2012 compliance
Notes	A recursion exists when a function calls itself directly or indirectly through another function call.
Rationale	Promote bounded function call behavior.
Model Advisor Checks	Check usage of recursions (Simulink Check)
References	IEC 61508-3, Table B.1 (6) 'Limited use of recursion' IEC 62304, 5.5.3 - Software Unit acceptance criteria ISO 26262-6, Table 6 (1j) 'No recursions' EN 50128, Table A.12 (6) 'Limited Use of Recursion' DO-331, Section MB.6.3.2.g 'Algorithms are accurate' DO-331, Section MB.6.3.3.d 'Software architecture is verifiable' MISRA C:2012, Rule 17.2
Last Changed	R2021a
Examples	There are multiple patterns in Stateflow® that can result in recursion. Recursive Function Calls
	When the default state A is entered, event Evn is broadcast in the entry action of A. Evn results in a recursive call of the interpretation algorithm. Since A is active, the outgoing transition of A is tested. Since the current event Evn matches the transition event (and because of the absence of condition) the condition action is executed, broadcasting Evn again. This results in a new call of the interpretation algorithm which repeats the same sequence of steps until stack overflow. Recursive Function Calls

hisf_0013: Usage of transition paths (crossing parallel state boundaries)

ID: Title	hisf_0013: Usage of transition paths (crossing parallel state boundaries)
Description	To avoid creating diagrams that are hard to understand,
	A	Avoid creating transitions that cross from one parallel state to another.
Notes	You can use this guideline to maintain a modeling language subset in high-integrity projects.
Rationale	A	Enhance model readability.
Model Advisor Checks	Check Stateflow charts for transition paths that cross parallel state boundaries (Simulink Check)
References	IEC 61508-3, Table A.3 (3) 'Language subset’ IEC 62304, 5.5.3 - Software Unit acceptance criteria ISO 26262-6, Table 1 (1b) 'Use of language subsets' EN 50128, Table A.4 (11) 'Language Subset' DO-331, Section MB.6.3.2.b 'Low-level requirements are accurate and consistent'
Last Changed	R2017b
Example	In the following example, when Out_A is 4, both parent states (A_Parent and B_Parent) are reentered. Reentering the parent states resets the values of Out_A and Out_B to zero.

hisf_0014: Usage of transition paths (passing through states)

ID: Title	hisf_0014: Usage of transition paths (passing through states)
Description	To avoid creating diagrams that are confusing and include transition paths without benefit,
	A	Avoid transition paths that go into and out of a state without ending on a substate.
Notes	You can use this guideline to maintain a modeling language subset in high-integrity projects.
Rationale	A	Enhance model readability.
Model Advisor Checks	Check for inappropriate use of transition paths (Simulink Check)
References	IEC 61508-3, Table A.3 (3) 'Language subset’ IEC 62304, 5.5.3 - Software Unit acceptance criteria ISO 26262-6, Table 1 (1b) 'Use of language subsets' EN 50128, Table A.4 (11) 'Language Subset' DDO-331, Section MB.6.3.2.b 'Low-level requirements are accurate and consistent'
Last Changed	R2018b
Examples

hisf_0015: Strong data typing (casting variables and parameters in expressions)

ID: Title	hisf_0015: Strong data typing (casting variables and parameters in expressions)
Description	To facilitate strong data typing, explicitly type cast variables and parameters of different data types in Stateflow.
Notes	The Stateflow software automatically casts variables of different type into the same data type. This guideline helps clarify data types of the intermediate variables.
Rationale	A	Apply strong data typing.
Model Advisor Checks	Check Stateflow charts for strong data typing (Simulink Check)
References	IEC 61508-3, Table A.3 (2) ‘Strongly typed programming language’ IEC 62304, 5.5.3 - Software Unit acceptance criteria ISO 26262-6, Table 1 (1c) 'Enforcement of strong typing' EN 50128, Table A.4 (8) 'Strongly Typed Programming Language' DO-331, Section MB.6.3.2.g 'Algorithms are accurate' MISRA C:2012, Rule 10.1 MISRA C:2012, Rule 12.2
Last Changed	R2021a
Examples	Recommended Not Recommended

hisf_0016: Stateflow port names

ID: Title	hisf_0016: Stateflow port names
Description	The name of a Stateflow input or output must be the same as the corresponding signal. An exception to the guideline is that reusable Stateflow blocks can have different port names.
Rationale	Support generation of traceable code.
Model Advisor Checks	Check naming of ports in Stateflow charts (Simulink Check)
References	DO-331, Section MB.6.3.2.b 'Low-level requirements are accurate and consistent' IEC 61508-3, Table A.3 (3) 'Language subset' IEC 62304, 5.5.3 - Software Unit acceptance criteria ISO 26262-6, Table 1 (1b) 'Use of language subsets' EN 50128, Table A.4 (11) 'Language Subset'
Last Changed	2018a

hisf_0017: Stateflow data object scoping

ID: Title	hisf_0017: Stateflow data object scoping
Description	Stateflow data objects with local scope must be defined at the chart level or below.
Rationale	Support generation of traceable code.
Model Advisor Checks	Check scoping of Stateflow data objects (Simulink Check)
References	DO-331, Section MB.6.3.2.b 'Low-level requirements are accurate and consistent' IEC 61508-3, Table A.3 (3) 'Language subset' IEC 62304, 5.5.3 - Software Unit acceptance criteria ISO 26262-6, Table 1 (1b) 'Use of language subsets' EN 50128, Table A.4 (11) 'Language Subset'
Last Changed	2018a
Examples	Recommended Not Recommended