Prevent the Fixed-Point Tool from Overriding Integer Data Types

When performing data type override (DTO) on a selected system, the Fixed-Point Tool overrides the output data types of each block in the system. The only blocks that are never affected by DTO are blocks with boolean or enumerated output data types, and blocks that are untouched by DTO by design (for example, lookup table blocks). Depending on your application, you might want to preserve the data type of certain signals, for example, blocks that represent indices.

To prevent the Fixed-Point Tool from overriding the data type of a specific block, set the DataTypeOverride setting of the numeric type of the block to Off.

1. Open the Block Parameters dialog box by double-clicking the block.

2. Under the Signal Attributes tab, in the Output data type field, specify the desired data type and set the et DataTypeOverride property to Off.

   

You can set this override to off at the command line by changing the Data Type Override setting of a signal’s numerictype. In this example, the output data type of this block remains a built-in uint8 even after performing data type override.

Alternatively, you can prevent the Fixed-Point Tool from replacing the current data type by using the Lock output data type setting against changes by the fixed-point tools parameter that is available on many blocks.