SD card affecting RTC

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Anonymous
Not applicable

I am having a weird issue with a board I designed using the 68-QFN packaged PSoC 5. Whenever I insert the mico SD card into my board, the RTC seems to stop working as in it fails to count or increment. This does not happen using the dev kit however so I am a little confused. For the layout of the PSoC chip, I followed the recommenced layout in the datasheet and am powering it though a 5V regulator. The RTC is using the internal XTAL 32 kHz clock. The micro SD card connector is routed directly to assigned PSoC 5 pins since, I believe, its logic level is 3.3V. Using a logic analyzer, I can see that whenever the SD card was removed, the RTC would count correctly and when the SD card was inserted the RTC would just remain at the time I set it to on startup. Any ideas? (The SD card does read and write correctly by the way)

   

Thanks

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4 Replies
Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Did you already check the interrupt priorities?

   

Can you please post your complete project, so that we all can have a look at all of your settings. To do so, use
Creator->File->Create Workspace Bundle (minimal)
and attach the resulting file.

   

 

   

Bob

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Anonymous
Not applicable

Thanks for the quick reply. Let me know if there's anything else I can provide. 

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Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

All your interrupts have got the same (lowest) priority.

   

In .cydwr view under "Interrupt" tab you may change the priorities from 7 (default, lowest) to other values.

   

Avoid to use priority 0 (highest).

   

I would try

   

RTC prio 7

   

SD prio 5

   

all others prio 6

   

 

   

Bob

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Anonymous
Not applicable

Didn't solve the issue. I tried other priorities also with no luck. 

   

Thanks

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