TMS320F280049C: HRPWM - SFO Failure Scenarios

Part Number: TMS320F280049C

Hello,

SFO V8 calibration function (SFO()) can return an SFO_ERROR in some circumstances. What are those? The readme.txt for the f28004x HRPWM library states the following:

//
// SFO function returns 2 if an error occurs & # of MEP
// steps/coarse step exceeds maximum of 255.
//

Could someone elaborate on the above?

Thank you.