Simulink Single Precision Conversion

Single-Precision Conversion for Simulink Models (Fixed-Point Designer)

Toolbox: Fixed-Point Designer

Function: DataTypeWorkflow.Single.convertToSingle

Converts user-specified double-precision data types — across block settings, Stateflow chart

settings, signal objects, and bus objects — to single precision. **Boolean, built-in integer

(int8, uint8, int16, …), and fixed-point types are left unchanged.**

When to Use

• Converting a Simulink model (.slx) or subsystem from double-precision to single-precision
• Reducing memory footprint for embedded hardware with native single-precision support
• Batch/CI conversions, checking conversion compatibility, or verifying no stowaway doubles remain
• Summarizing the single conversion compatibility report and conversion result for the user in plain language

When NOT to Use

• Standalone MATLAB .m code — use the convertToSingle function with coder.config('single') instead
• Fixed-point data type optimization — use DataTypeWorkflow.Converter instead

Public API

ConversionReport = DataTypeWorkflow.Single.convertToSingle(systemToConvert)

• systemToConvert (char) — full block path of the loaded model or subsystem (e.g. 'myModel' or 'myModel/Controller').
• ConversionReport (struct) — compatibility check, converted items, and verification status (see field tables below).

Worked example: openExample("fixedpoint/ConvertSystemToSinglePrecisionExample")

Rules

• Open with open_system(modelName), not load_system — the user must see the diagram before/after.
• Never call save_system — saving destroys the double-precision baseline and blocks meaningful re-runs. Leave the model dirty; persist only if the user explicitly asks.
• The compatibility check runs *inside* convertToSingle; read its results from report.CheckInfo (it is not a separate call).
• Get the user's explicit consent before converting. If the model path, subsystem, or scope is ambiguous, ask.
• Always inspect report.VerifyInfo.StowawayDblBlks afterward — remaining stowaway doubles mean the conversion is incomplete.
• Assign the report to a local variable (report = ...;) — don't pollute the base workspace or echo the raw struct.

Report Structure

The tool runs check → convert → verify, populating three sub-structs on the report.

report.CheckInfo

| Field | Description |

|-------|-------------|

| ready | Logical — true if the system can be converted |

| err | Error info (empty on success) |

| IncompatibleBlks | Blocks not supporting single precision |

| UnsupportedBlks | Blocks unsupported by the conversion tool (with ErrorMsgs) |

| DTLockedDblBlks | Blocks with locked double data types (do not block conversion) |

| StowawayDblBlks | Blocks generating double operations found during the check |

| TLSSettings | Models whose Target Language Standard was updated to C99 |

| DTOSettings | Systems whose Data Type Override was reset |

| SolverSettings | Models whose variable-step solver was changed to fixed-step |

| configSettings | Config params updated (e.g. GenerateComments, ParameterPrecisionLossMsg) |

| memoryUse.BeforeValue | Per-parameter memory table; column RuntimeMemory (bytes) before conversion |

report.ConvertInfo

Records what the converter actually did.

| Field | Description |

|-------|-------------|

| ready | Logical — true if the convert step ran cleanly |

| err | Error info; empty ([]) on success |

| results | Cell array of fxptds.BlockResult — the blocks/signals changed from double to single |

report.VerifyInfo

| Field | Description |

|-------|-------------|

| StowawayDblBlks | Blocks still generating double operations after conversion |

| memoryUse.AfterValue | Per-parameter memory table; column RuntimeMemory (bytes) after conversion |

The check phase validates the Target Language Standard, Data Type Override, incompatible

blocks, stowaway doubles, data-type-locked doubles, and solver settings — and auto-updates

several of them. **The tool handles TLS→C99, DTO cleanup, and solver changes automatically;

you do not need to set these manually.** See references/edge-cases.md

for the full auto-update behavior, error identifiers, and edge cases:

• Model not loaded / invalid path (Simulink:Commands:InvSimulinkObjectName); update-diagram failures (DataTypeWorkflow:Single:UpdateDiagramFailed)
• Incompatible blocks (continuous blocks, MATLAB System blocks) and unsupported MATLAB Function Blocks (globals, MCOS classes, Simulink function calls)
• Auto-updates (TLS, DTO, solver, config), model-reference scope handling, idempotency, and cleanup on model close

Generating the Conversion Report

After convertToSingle returns, summarize the result for the user in plain language — do not

dump the raw struct. Put the exact API call used at the top for traceability.

For the required output sections, empty-report fallback, reporting conventions, and the

Embedded Coder readiness-check follow-up, see references/reporting-format.md.

Prerequisites & Limitations

• Requires MATLAB, Simulink, and Fixed-Point Designer; the model must be loaded.
• The conversion engine is a singleton — only one conversion session can be active at a time.
• MATLAB Function Blocks with complex logic and model references may need individual review — see references/edge-cases.md.

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Copyright 2026 The MathWorks, Inc.

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