This example shows how to interpret the Intermediate Maximum and Intermediate Minimum results in the Result Details tab.
Open the model. At the MATLAB® command line, enter:
Update the diagram. Notice the design range information for each of the input ports.
Open the Fixed-Point Tool. From the model menu, select Analysis > Data Type Design > Fixed-Point Tool.
In the Fixed-Point Tool, in the Prepare System section of
the toolstrip, under System under design, select
ex_intermediateRange as the system you want to
In the Collect Ranges section of the toolstrip, select Derived Ranges.
Click the Collect Ranges button.
The Fixed-Point Tool displays the derived minimum and maximum values for each object in the
In the Convert Data Types section of the toolstrip, open the Settings menu.
In the Default word length field, enter
Click the Propose Data Types button .
The tool displays the proposed data types appear in the spreadsheet.
Look at the proposed data type of the Product block. The Fixed-Point Tool proposed a data type with 32-bit word length and 12-bit fraction length. The derived maximum value of the Product block is 1, but the maximum representable value for the proposed data type is approximately 1,048,575.
To learn more about the data type proposal, select the product block in the spreadsheet. The Result Details pane populates with information about the result.
In the Result Details, in the Range Information table, notice the row labeled Intermediate. After the first two inputs to the Product block are multiplied, the block has a maximum value of 1000000 before being multiplied by the next two inputs for a final maximum value of 1. The data type proposal for the Product block in this model is based on the intermediate minimum and maximum values. It is not based on the derived minimum and maximum values to prevent overflows at the intermediate stages of the block.