questions about the RTI

Jiaming Sun

Other Parts Discussed in Thread: HALCOGEN

Hi,all

tick = RTI_CNT_FRCx - (RTI_CMP_COMPx - RTI_CMP_UDCPx);

I don't understand why RTI_CNT_FRCx needs minus (RTI_CMP_COMPx - RTI_CMP_UDCPx); what does this mean?

If I use tick = RTI_CNT_FRCx - (RTI_CMP_COMPx - RTI_CMP_UDCPx),the number can't go large ,if I delete (RTI_CMP_COMPx - RTI_CMP_UDCPx);,the number seems good.

over 12 years ago

0 KARTHIKEYAN RAJAMANICKAM over 12 years ago

TI__Genius 11645 points

Hi,

Can you pls let us know on what context this piece of code is being referred from ?

0 Jiaming Sun over 12 years ago in reply to KARTHIKEYAN RAJAMANICKAM

Expert 1300 points

the code is in funcition "uint32 rtiGetCurrentTick(uint32 compare)" in file 'rti.c' which is gererated by HALCOGEN for KEIL

I want to use the freetimer ,so I use the function "uint32 rtiGetCurrentTick(uint32 compare);"

0 KARTHIKEYAN RAJAMANICKAM over 12 years ago in reply to Jiaming Sun

TI__Genius 11645 points

Jaiming,

Not sure what your requirement looks like, but I will try to give you an idea of what rtiGetCurrentTick() returns with this small example. Assuming I need a tick for every 50 FRC cycles, then at some given instance if I need to know how many FRC cycles are completed after the last tick, thats exactly what this function returns.

Lets assume FRC goes from 0 to 1000... and,
COMPx = 50
UDCMPx = 50

so for every FRC count ,we will see what CurrentTick value this function will return as shown below,

Best Regards,

Karthik.

0 Jiaming Sun over 12 years ago in reply to KARTHIKEYAN RAJAMANICKAM

Expert 1300 points

I understand your meaning ,my requirement is to count the FRC cycles since programs start to the time I count the FRC cycles ,the number may be very large

0 KARTHIKEYAN RAJAMANICKAM over 12 years ago in reply to Jiaming Sun

TI__Genius 11645 points

If that's what you need and if you believe the FRC will expire since you are counting a lot of cycles, then please use a larger value in CPUCx(Compare Up Counter x Register ), which will control the pace of your FRC.

Hope that answers your question.

0 KARTHIKEYAN RAJAMANICKAM over 11 years ago in reply to KARTHIKEYAN RAJAMANICKAM

TI__Genius 11645 points

Jaiming,

If the above answers your question, please click verify answer and close this thread. Thanks.

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