TMS320F28022: Transmit only for use with C2000/AFE031 App Note, replaces TMS320F28379

Part Number:TMS320F28022

Hello,

We are porting the transmit-only software example for this app note (http://www.ti.com/lit/an/sprac94b/sprac94b.pdf

This uses 2 HRPWM outputs on GPIO0 and GPIO2.

We've gotten pretty close but the HRPWM output is still a little off from the desired frequency.

• The output on GPIO0 needs to be 131.25kHz but the closest we have gotten is 131.205kHz. This a 2.6ns variation or about 14.5 HRPWM cycles.
• We changed the EPwm1Regs.TBPRD register to 1 + (CLK_FREQ / SPACE_FREQ) which got us from 17ns off to 2.6ns off.

What register we can use now to fine tune this last 2.6ns variation? We are thinking there might be a HRPWM register we can alter.

Thanks!