Multi Slow speed PWM and Instant Interrupts

[aberco]

Yes I understand that it is very CPU intensive... Here's the settings for the PWM:

CPU @ 48Mhz 3 PWM channels with
DEFINE SPWM_FREQ 100 'SPWM Frequency
DEFINE SPWM_RES 256 'SPWM Resolution

I tried dropping SPWM_FREQ to 40 and SPWM_RES 100 but it is still very irregular. It works well when de D+/D- lines are disconnected, so there's good chances the USB interrupt does takes too much time.

USB INT does contains much more than just USBSERVICE. There's about a dozen PBP instructions to update de status of "Plugged, RX_READY and TX_READY" and this is why I have it as a PBP interrupt. Tried turning it into an ASM interrupt and it does work too, but that's very confusing to me??!

[Darrel Taylor]

It's called "USB_ASM_Service" for a reason.
It's ASM compatible, even though it uses some PBP syntax.

Those PBP statements don't use any of PBP's system registers.

When you made it ASM, was it also Low Priority?

[aberco]

Hey Darrel, ok I understand "ASM" better.

I have everything as high priority interrupt and deleted all my little tweaking attempt. I got it to work nicely now, even with SPWM_FREQ 200. I however don't understand why at first it was not working as is, must have done something wrong

Anyway thanks for your help! this is a great routine!