32khz xtal not stable or close to 32khz? Psoc 5 kit

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SalinaSJames
Level 1
Level 1
First reply posted First question asked Welcome!

Trying to use the RTC component, seconds advance appx 1/5th speed.

I routed the clock to a pin to scope it, the signal bounces between 4 and 7 kHz, and definitely isn't square. I expected some distortion from lengthening the wires, but this is excessive.

I even loaded a blank project, with just the clock and pin, no change.

From what I can find, the in internal crystal is either enabled or not, I cant find any adjustments.

Suggestions on where to shagle voojio look?

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SalinaSJames,

The watch crystal support in the PSoC5 requires an external crystal.  There is no watch crystal on the CY8CKIT-059.  However, the CY8CKIT-050 has a watch crystal on-board.

Watch crystals can be fairly inexpensive.  The last time I bought one it was about 15 cents.

Len
"Engineering is an Art. The Art of Compromise."

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Len_CONSULTRON
Level 9
Level 9
Beta tester 500 solutions authored 1000 replies posted

SalinaSJames,

Here are some questions for you for others to better answer your inquiry?  (There is some confusion since you placed this discussion on the PSoC4 forum.)

  • What PSoC4 part are you using?
  • Are you using a Cypress/Infineon evaluation board?
  • What pins are you using for connecting the 32.768K crystal?   (For the XTAL32K oscillator only specific pins are used.)

I've used the 32K watch crystal with the PSoC5 and have very good and consistent oscillations.

I've attached a very simple project that invokes the XTAL_32K oscillator.  It routes this signal to an output pin.

Here's a picture of the scope trace of the pin (P2.0).   It is 32.7KHz and stable.  Note:  It is NOT 50% duty cycle.  The oscillator does not guarantee 50%.  If you need a 50% signal, pass this signal through a div2.  It will deliver 50% DC at 16.384KHz.

PRINT_25.png

Len
"Engineering is an Art. The Art of Compromise."
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SalinaSJames
Level 1
Level 1
First reply posted First question asked Welcome!

https://www.cypress.com/file/123561/download

I found this (p105/106), everything else led me to believe there was an internal OR optional external 32khz crystal. Their sales pitches are not clear... I had the impression that I simply needed to initialize the crystal an it would work.

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SalinaSJames,

The watch crystal support in the PSoC5 requires an external crystal.  There is no watch crystal on the CY8CKIT-059.  However, the CY8CKIT-050 has a watch crystal on-board.

Watch crystals can be fairly inexpensive.  The last time I bought one it was about 15 cents.

Len
"Engineering is an Art. The Art of Compromise."
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