LAUNCHXL-F28379D: ePWM Trip Zone issue

Hi,

Trip zone is active low input.

You can refer to example here -
C:\ti\c2000\C2000Ware_2_00_00_03\driverlib\f2837xd\examples\cpu1\epwm
epwm_ex1_trip_zone

Thanks for the reply.

I have already seen the example. I have set all registers but still it is not working. Tried it with both active high and low inputs, and still the PWM output was not forced to low.

Hi,

When you run the example as it is, does it work? Do you see any issues with example as well?

I have set the below registers and bits:

For GPIO:

GpioCtrlRegs.GPBGMUX1.bit.GPIO32 = 0;

GpioCtrlRegs.GPBMUX1.bit.GPIO32 = 0;

GpioCtrlRegs.GPBDIR.bit.GPIO32 = 0;  //Set as input

GpioCtrlRegs.GPBINV.bit.GPIO32 = 1;   //Invertered because circuit connected gives a high on fault

Xbar:

InputXbarRegs.INPUT1SELECT = 32;  // Feed GPIO32 to ePWM[TZ1]

In PWM settings:

EPwm1Regs.TZSEL.bit.OSHT1 = 1; //Enable TZ1 as one shot trip

EPwm1Regs.TZCTL.bit.TZA = 2; // Force PWM low

EPwm1Regs.TZEINT.all = 0x0000;  // Trip Zone Interrupt Disabled

Did I miss something, please?

Subrahmanya said:

Hi,

When you run the example as it is, does it work? Do you see any issues with example as well?

The example does not run since it seems that it references a lot of functions not in the project.

Dan8 said:

I have set the below registers and bits:

For GPIO:

GpioCtrlRegs.GPBGMUX1.bit.GPIO32 = 0;

GpioCtrlRegs.GPBMUX1.bit.GPIO32 = 0;

GpioCtrlRegs.GPBDIR.bit.GPIO32 = 0;  //Set as input

GpioCtrlRegs.GPBINV.bit.GPIO32 = 1;   //Invertered because circuit connected gives a high on fault

Xbar:

InputXbarRegs.INPUT1SELECT = 32;  // Feed GPIO32 to ePWM[TZ1]

In PWM settings:

EPwm1Regs.TZSEL.bit.OSHT1 = 1; //Enable TZ1 as one shot trip

EPwm1Regs.TZCTL.bit.TZA = 2; // Force PWM low

EPwm1Regs.TZEINT.all = 0x0000;  // Trip Zone Interrupt Disabled

Did I miss something, please?

Hello,

Anything missing in my code, please?

Hi,

Dan8 said:

Anything missing in my code, please?

Configuration looks correct.

That's the reason i'm suggesting you try out the example. All the dependent files should be part of the C2000Ware.

Are you using controlSuite based code? If so, example can be found here.
C:\ti\controlSUITE\device_support\F2837xD\v210\F2837xD_examples_Cpu1\epwm_trip_zone

Subrahmanya said:

Configuration looks correct.

That's the reason i'm suggesting you try out the example. All the dependent files should be part of the C2000Ware.

Are you using controlSuite based code? If so, example can be found here.
C:\ti\controlSUITE\device_support\F2837xD\v210\F2837xD_examples_Cpu1\epwm_trip_zone

Hi,

I am trying to debug the example. What do I need to monitor to see the code working? Also I do not think I have access to pin GPIO12 from the development board contacts.

Hi,

Were you able to resolve this issue?
As mentioned in the testcase header, You can monitor

//! - EPWM1A is on GPIO0
//! - EPWM2A is on GPIO2
//! - TZ1 is on GPIO12

Subrahmanya said:

Hi,

Were you able to resolve this issue?
As mentioned in the testcase header, You can monitor

//! - EPWM1A is on GPIO0
//! - EPWM2A is on GPIO2
//! - TZ1 is on GPIO12

Unfortunately no, I cannot access GPIO12 from my development board. In addition I would like to set TZ1 on GPIO32 but it is not working.

Hi,

Xbar:

InputXbarRegs.INPUT1SELECT = 32;  // Feed GPIO32 to ePWM[TZ1]

This should have addressed the change needed from GPIO12 to GPIO32.
Is there anything else on your application board driving GPIO32?

It would be good if you can run the test (example) and have it working for easier debug. 

Subrahmanya said:

Hi,

Xbar:

InputXbarRegs.INPUT1SELECT = 32;  // Feed GPIO32 to ePWM[TZ1]

This should have addressed the change needed from GPIO12 to GPIO32.
Is there anything else on your application board driving GPIO32?

No nothing else is connected to that input.

Hi,

Do you have any other hardware platform like a controlCard/docking station or so?
Also, could you check with some other GPIO other than GPIO32?
Since the test case configuration is pretty straightforward - I do not see any this incorrect in the code you sent above.
How do you plan to close this? It may be easier to narrow down the problem if you get a working set up with the example as is and no additional h/w.

Subrahmanya said:

Hi,

Do you have any other hardware platform like a controlCard/docking station or so?
Also, could you check with some other GPIO other than GPIO32?
Since the test case configuration is pretty straightforward - I do not see any this incorrect in the code you sent above.
How do you plan to close this? It may be easier to narrow down the problem if you get a working set up with the example as is and no additional h/w.

Yes I tried with other GPIO inputs and it is the same.

Hi,

Can you also respond to other questions in the previous post?

Do you have any other hardware platform like a controlCard/docking station or so?
Also, could you check with some other GPIO other than GPIO32?
Since the test case configuration is pretty straightforward - I do not see any this incorrect in the code you sent above.
How do you plan to close this? It may be easier to narrow down the problem if you get a working set up with the example as is and no additional h/w.

Subrahmanya said:

Hi,

Can you also respond to other questions in the previous post?

Do you have any other hardware platform like a controlCard/docking station or so?
Also, could you check with some other GPIO other than GPIO32?
Since the test case configuration is pretty straightforward - I do not see any this incorrect in the code you sent above.
How do you plan to close this? It may be easier to narrow down the problem if you get a working set up with the example as is and no additional h/w.

I have only the Launchpad (more than one - tried them with same issue). As stated earlier I have tried with different GPIO pins and still the Trip zone does not work. To test if the change on the pin is being seen by the ucontroller, I have also enabled the interrupt caused by the Trip zone to switch off an LED on the Launch pad but it does not switches off. Meaning that the Trip zone is not being recognized.

Regarding the sample example program, it is giving me an error on compiling due to the need of files or functions that are not available in the project. Which I cannot find in Code Composer. There is also the issue of GPIO12 which is not available on the header pins on the Launch pad, but that can be changed to another pin.

For now I am testing without any additional hardware. I am just trying to cause a trip event by providing 3V or 0V to GPIO32 using the Launch pad header pins. In the end I need to attach the Launch pad on another PCB to operate a converter. The trip event is needed to switch off the PWM in case of a fault in the converter, causing the pin to go to high.

Hi,

Dan8 said:

Regarding the sample example program, it is giving me an error on compiling due to the need of files or functions that are not available in the project. Which I cannot find in Code Composer. There is also the issue of GPIO12 which is not available on the header pins on the Launch pad, but that can be changed to another pin.

Hi,

Have you been able to capture some screenshots of the CCS error you are seeing (if you are still facing this issue)?

Best,

Marlyn

Marlyn Rosales Castaneda20 said:

Hi,

Have you been able to capture some screenshots of the CCS error you are seeing (if you are still facing this issue)?

Best,

Marlyn

There is no errors listed, the Trip zone is not working, and I am still with the problem after weeks. Can someone offer some support, please? This is needed for a prototype.

Hi,

I've checked the example again on LAUNCHXL_F28379D by changing the GPIO12--> to GPIO32 and GPIO11 --> GPIO19 as per your use and to make use of the GPIOs are available on Launch Pad. This test works as expected and PWM is tripped.

Subrahmanya said:

Hi,

I've checked the example again on LAUNCHXL_F28379D by changing the GPIO12--> to GPIO32 and GPIO11 --> GPIO19 as per your use and to make use of the GPIOs are available on Launch Pad. This test works as expected and PWM is tripped.

I do not know what is happening. I think I have everything set up correctly. I will give it another go and get back.

Hi,

Sure - please try and debug. This is fairly basic configuration and a simple test case.

By any chance is Trip Zone 1 TZ1 only available on GPIO12?

Hi Dan,

I find it odd you are not enabling the trip zone interrupt. So how do you intend to clear the latched fault GEN condition if not by the fault INT handler?

TM4C1294 MCU has GenModeFaultNoMinper being latched fault condition, FaultMinper rest timeout register determines how long disabled GEN output condition takes.

BP101 said:

Hi Dan,

I find it odd you are not enabling the trip zone interrupt. So how do you intend to clear the latched fault GEN condition if not by the fault INT handler?

TM4C1294 MCU has GenModeFaultNoMinper being latched fault condition, FaultMinper rest timeout register determines how long disabled GEN output condition takes.

I was thinking of resetting the MCU manually.

Hi,

No, any GPIO can be used as trip zone input.
If you've gone through the example code, device documentation you would notice that any GPIO can be configured via InputXbar as Trip input.
Also I mentioned above that the example is tested with GPIO32 as well.
Thank you.

Was not enabled in his posted code beginning of thread. He could not get the example to compile with the F28379 as I read many times Dan tired.

Point is unless you have scope set on single capture you may miss the Fault event ever occurring if there is no latch enable or timeout being set for Minper.

EPwm1Regs.TZSEL.bit.OSHT1 = 1; //Enable TZ1 as one shot trip

How long is the one shot fault trip set for?

BP101 said:

?

1	EPwm1Regs.TZSEL.bit.OSHT1 = 1; //Enable TZ1 as one shot trip

How long is the one shot fault trip set for?

I understood that a one shot trip is until MCU reset. Or no?

So it's a latched one shot PWM trip zone by default? Such odd syntax makes for some crazy coding in C2000, simply judging from the labs structures.

Hi,

No - it's not default. you need to enable trip zone as One Shot - if that's what is intended for your application.

For TM4C1294 we have to specify the gen fault behavior is latched (Minper) or a timed fault auto recovery (NoMinper). I was told that had become an industry standard of ePWM modules. So C2000 PWM generators enabled one shot tip zones are NoMinper (latched), otherwise default Minper without one shot trip zone enabled?

Anyway if trip zone is not latched in some way the event may occur so rapidly it can be easily missed via scope set to auto trigger mode.   

Interesting flags the ePWM has trip zones much like Minper/NoMinper. And not very well documented but it seems the fault type/mode has to be configured in each module? Perhaps TZLCTL is a key register for the fault mode? The CBC cycle by cycle seemingly is NoMinper... 

f28004x_epwm.h

    union   TZSEL_REG                        TZSEL;                        // Trip Zone Select Register
    Uint16                                   rsvd24;                       // Reserved
    union   TZDCSEL_REG                      TZDCSEL;                      // Trip Zone Digital Comparator Select Register
    Uint16                                   rsvd25;                       // Reserved
    union   TZCTL_REG                        TZCTL;                        // Trip Zone Control Register
    union   TZCTL2_REG                       TZCTL2;                       // Additional Trip Zone Control Register
    union   TZCTLDCA_REG                     TZCTLDCA;                     // Trip Zone Control Register Digital Compare A
    union   TZCTLDCB_REG                     TZCTLDCB;                     // Trip Zone Control Register Digital Compare B
    Uint16                                   rsvd26[5];                    // Reserved
    union   TZEINT_REG                       TZEINT;                       // Trip Zone Enable Interrupt Register
    Uint16                                   rsvd27[5];                    // Reserved
    union   TZFLG_REG                        TZFLG;                        // Trip Zone Flag Register
    union   TZCBCFLG_REG                     TZCBCFLG;                     // Trip Zone CBC Flag Register
    union   TZOSTFLG_REG                     TZOSTFLG;                     // Trip Zone OST Flag Register
    Uint16                                   rsvd28;                       // Reserved
    union   TZCLR_REG                        TZCLR;                        // Trip Zone Clear Register
    union   TZCBCCLR_REG                     TZCBCCLR;                     // Trip Zone CBC Clear Register
    union   TZOSTCLR_REG                     TZOSTCLR;                     // Trip Zone OST Clear Register
    Uint16                                   rsvd29;                       // Reserved
    union   TZFRC_REG                        TZFRC;                        // Trip Zone Force Register
    Uint16                                   rsvd30[8];                    // Reserved
    union   ETSEL_REG                        ETSEL;                        // Event Trigger Selection Register