S9KEA Oscillator don't start while debugger connected

[michaelkrause]

Hi,

running S9KEA64 or S9KEA32 with external resonator/quartz is working. But, if I connect the debugger to the system, it leads to not starting of oscillator.

Does anybody know if this is a bug/feature of KEA chip or might be due to the debugger?

Michael

[Choongryeol-Lee]

Has this problem been resolved?

[Hui_Ma]

Hi Michael,

Have you tried to use the oscillator high gain mode?

Could you post your clock circuit and debugger circuit for double check?

Which debugger tool you are using?

Have a great day,
Ma Hui

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[michaelkrause]

Hi,

thx for reply. Yes, I've tried to use high gain mode. I also tried the use of normal 4MHz crystal with caps and MURATA resonator (2x 39pF included). (While high gain mode used RF = 1MOhm). RS = 0

The oscillator is running well while running stand alone. If debugger is connected it doesn't start.

Debugger "blue box"  ic5000 comes from company iSystem.com and it's connected to single wire debug port. Hence there is no connection to XTAL or EXTAL.

As SWD port is declared to be non intrusive, just wondering what is happening (and why?). Can't find any hint in specification paperworxx

Michael

[Hui_Ma]

Hi Michael,

Sorry for the later reply.

Could you provide the 4MHz crystal manufacture's datasheet?

If the 39pF load capacitor value is 4MHz crystal recommendation value?

Have a great day,
Ma Hui

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[michaelkrause]

Hi,

I'm using MURATA CSTCR4M00G35B resonator, it has build in 39pF and resonant impedance is 60.

That one is working fine.

I'm wondering why it will not start when debugger is connected.

[michaelkrause]

Hi,

thx for replay. While debug session, code is captured in this loop:

while(!(OSC_CR & OSC_CR_OSCINIT_MASK));

As, oscillator is not running, this is plausible.

Attached code is well known and used, hence doesn't change root cause.

My personal point of view is that usage SWD is influencing the OSC.

If this is true, it's a bit uncomfortable but no showstopper. I will ask debugger manufacturer if he has any knowledge about this. Suggest to idle this thread, until his feedback.

cordialment/

Michael

[Hui_Ma]

Hi,

Sorry, we have no experience using BlueBox iC5000 debugger tool.

When you debug the code, if the code was stop at below code?

while(ICS_S & ICS_S_IREFST_MASK);

And if the external crystal doesn't start to oscillate in debug mode?

I would recommend customer to refer the ICS driver code attached and try the FEI_to_FEE_OSC() code during initialization.

Wish it helps.

Have a great day,
Ma Hui

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