CCS/TMS320F28335: Time register in eCAP function have a very small value

Hi Faris,

I am checking with eCAP expert. I will get back to you by tomorrow.

Faris,

Can you provide more information on how the green graph is ploted and also, can you send the values of DutyOnTime1?

Hi santosh, 

the green graph is ploted by multiplying the register value in DutyOnTime1 with 6.67ns and multiplied again by 1000 to make it in ms unit. i am sorry, i didnt take a picture about the values on DutyOnTime1 but when the register value is 124xxxxx the value is correct (around 8) but sometimes the register value is so small, around 33, or 120, or 27 like that so when we multiply it by 6.67ns and 1000 the value almost zero. Also this is occurs on all register, it occurs on DutyOffTime1, DutyOnTime2, and DutyOffTime2 but at different time. 

Thanks,

Faris

Faris,

Do you have simplified project which we can use to reproduce it?

Dear santosh, i am sorry, i don't have the simplified version of the code. Actually i just use the code from sprui07 reference file. I use the rising and falling edge delta time stamp capture. The problem is, sometimes the time register value is so small, as i mentioned before, it should be around 12xxxx but it appears only in two or three digits.

Thanks,

Faris

Faris,

I am trying to reproduce it here, so far no luck. I need to check with experts. I will get back to you on Oct 5th, Monday.

Dear Santosh,

thanks for your response, i look forward for the answer

Thanks,

Faris

Dear santosh,

I send you the picture from the CCS debug to clearly see the problem

The correct value should be like ECap1Regs.CAP2 and ECap1Regs.CAP3, but sometimes the value in timer register is so small (in this case it is ECap1Regs.CAP4 and ECap1Regs.CAP1). This abnormal condition happens in all timer counter register, not only the ECap1Regs.CAP4 and ECap1Regs.CAP1, sometimes the ECap1Regs.CAP2 and ECap1Regs.CAP3 also has value like that.

Thanks,

Faris

Hi Faris,

When you read very low values, can you capture eCAP registers?

Also, Can you check the input signal if there is a glitch in the input signal? 

Dear Santosh,

the eCAP registers value when low values occurs is 

also i check the input signal

the yellow graph is the input, as can be seen there is no glitch at the input

sorry for the late reply, i believe i already reply to you in monday

can you guide me how to using the interrupt from CEVT flag? i think if i use interrupt for capturing the time, the problem will be solved

thank you,

Faris

Faris,

When it is getting smaller values, can you read ECFLG register?

Also, how are you setting the Qualification mode for input GPIO line? Can you try with qualified 3-sample or qualified 6-sample mode?

GPIO_setQualificationMode(24,GPIO_QUAL_3SAMPLE);

dear santosh,

which ECFLG register should i see? i mean that register have many bits on there, which one should i see? actually, i can see the value of the register

for qualification mode, i use 1 sample mode, i will try the biggest one first

thanks,

Faris

Faris,

It will be good to check BIT1 to BIT7: (Please refer to table 5.13 in TRM)