Tutorial: Producing Lookup Table Data (Fixed-Point Blockset)

Fixed-Point Blockset

Data ROM Required

This section looks at the data ROM required by each of the three spacing options.

Uneven Case

Uneven spacing requires both Y data points and breakpoints:

int16_T  yuneven[8];
uint16_T xuneven[8];

The total bytes used is 32.

Even Case

Even spacing requires only Y data points:

```
int16_T yeven[10];
```

The total bytes used is 20. The breakpoints are not explicitly required. The code will use the spacing between the breakpoints, and may use the smallest and largest breakpoint. At most three values related to the breakpoints are needed.

Power of Two Case

Power of two spacing requires only Y data points:

```
int16_T ypow2[17];
```

The total bytes used is 34. The breakpoints are not explicitly required. The code will use the spacing between the breakpoints, and may use the smallest and largest breakpoint. At most three values related to the breakpoints are needed.

Effect of Spacing on Speed, Error, and Memory Usage Determining Out-of-Range Inputs