MC Fast abort

[lpcware]

Content originally posted in LPCWare by dscherbarth on Wed Nov 13 07:41:12 MST 2013
I am using an lpc1769 to control an ac induction motor.  I would like to use the 'Fast Abort' feature.  Has anyone implemented the fast abort (pad 4)?  I implemented the interrupt handler and enabled the fast abort interrupt (bit 15).  If i connect the pin to ground and start the code i get continuous interrupts until I disconnect the fast abort, then I can't get the int to fire again... also if the mc core is making a control waveform the fast abort seems to have no effect... any pointers would be welcome 

Thanks
Doug

[lpcware]

Content originally posted in LPCWare by praveenb on Mon Mar 16 23:12:52 MST 2015

Hi dscherbarth

Can u explain how to use fast abort pin, because i generated signal having 90 degree phase shift as shown in Fig 130.Quadrature Encoder Basic Operation of UM10360 data sheet,to run a motor in +ve and -ve direction, to check, is it +ve and -ve i used a QEI it showing direction and phase error i need to solve this please help

[lpcware]

Content originally posted in LPCWare by smartarseev on Mon Apr 07 01:51:44 MST 2014
I have a similar issue with Motor Control Fast Abort.

I want the Abort (Passive state) to remain until the next PWM cycle. Then enable normal PWM (abort IRQ cleared in this next cycle. This is how a normal current limit works in PWM on other processors. if a current limit event happens (Abort) then disable PWM until the next cycle and start up again. The system can remain in continuous current limit without damage (it limits the PWM width according to current).

The same problem occurs if I do not remove (clear) the Abort interrupt event (MCPWM_INTFLAG
_ABORT). It will continually interrupt with the Abort interrupt that is still pending. If I clear the Abort interrupt it removes the "safe" (Passive) Abort state and immediately starts to drive again (completing the PWM cycle). This makes the PWM waveform unstable and uncontrolled.

As I can see the LPC17 internal logic does not allow this type of current control with using the Abort pin, I want to try a work around, that leaves the Abort active and trigger another interrupt at the when the PWM counter gets to the end of the cycle (Limit value). In the Limit IRQ I will re-enable the Abort IRQ.

The Abort event (Passive state) can only occur if the interrupt is pending.

So here are my questions:
1) Is there a way to hold abort state and trigger one of the other MC interrupts (e.g MCPWM_INTFLAG
_LIM0)? I only get continuous interrupts from the Abort event - That I don't want to clear.

2) Can I get Abort sate (Passive state) without an Abort IRQ (MCPWM_INTFLAG_ABORT)? I need to keep MCPWM_IRQn active (enabled) to get other MC interrupts still.

Can only one help? Or have any ideas? Abort function seems very strange if it can only be used with an  associated IRQ...????

[lpcware]

Content originally posted in LPCWare by dscherbarth on Thu Nov 14 03:56:46 MST 2013
Hi, thanks for the response.  I am clearing the pending interrupts, i think i keep getting the interrupt because the MCABORT signal is active low (can't configure for edge).  I could do without the interrupt if nec, my main concern is to get the fast abort to abort making the motor waveform and that doe not seem to work at present...  Thanks again :-)

[lpcware]

Content originally posted in LPCWare by Pacman on Wed Nov 13 22:23:48 MST 2013
Uhm... I have no experience with MC or Fast Abort, but when reading about the symptoms, I thought of...

Did you remember to clear the pending interrupts in your IRQ handler ?