Texas Instruments TMS320 User Manual page 251

Stackable Devices
Figure 7-7. Sine Wave Output for Example 7-9
You can edit sioTest5.c and change the scaling factor of the DTR_PRMS,
rebuild the executable and see the differences in the output to myLog.
A version of Example 7-9, where the streams are created dynamically at
runtime by calling SIO_create is available in the product distribution
(siotest4.c, siotest4.cdb).
Streaming I/O and Device Drivers 7-21