Wireless MCUのトピックRe: K32W Xtal

K32W Xtal

danieltseng — Fri, 10 Jul 2020 14:05:12 GMT

Before, we can adjust the xtal of the connectivity test of KW41's smac, but I don't know how to achieve the frequency offset of K32W.

If the frequency of the customized board is shifted, how can I adjust K32W frequency ?

Re: K32W Xtal

mario_castaneda — Wed, 15 Jul 2020 04:59:15 GMT

Hi Daniel,

Please look at the fsl_clock.c file JN5189DK6\devices\JN5189\drivers\fsl_clock.c

CLOCK_Xtal32M_Trim();

Regards,

Mario

Re: K32W Xtal

danieltseng — Wed, 15 Jul 2020 06:33:57 GMT

These two tools (CMET and BLE CTUG) do not support frequency offset adjustment.
Are there other tools that can provide frequency adjustment?

Or what should I do to achieve the adjustment function?

Re: K32W Xtal

mario_castaneda — Thu, 16 Jul 2020 00:07:32 GMT

Hi Daniel,

Unfortunately, we do not provide a similar example for the K32W.

However, the CLOCK_Xtal32M_Trim API provides the parameters for the capacitance compensation and if temperature compensation is needed.

/*
 * param  XO_32M_OSC_CAP_Delta_x1000 Osc capacitance expressed in fF (femtoFarad).
 * Must be 0 if no temperature compensation algorithm is implemented for a given board
 *
 */
void CLOCK_Xtal32M_Trim(int32_t XO_32M_OSC_CAP_Delta_x1000, const ClockCapacitanceCompensation_t *capa_charac)‍‍‍‍‍‍

I am assuming that the customer is working with the JN5189 module. So, this trim xtal process is not needed.

There are two possibilities when trimming is needed

That the board layout design, board manufacturing, and component selection have repeatable values of resistance, capacitance, and inductance, resulting in a stable XTAL trim – The components and manufacturing process of the board are reliable enough, allowing you to characterize the XTAL trim during the system development and then use it every board during production.
That the design and component selection does not result in a stable XTAL trim – If there is considerable variation between different boards of the same design or components used in the board manufacturing, you would need to implement an XTAL trim procedure during the production process, and program the trim value.

Regards,

Mario

Re: K32W Xtal

danieltseng — Thu, 16 Jul 2020 08:50:33 GMT

Hi Mario:

I study HCI's CLOCK_Xtal32M_Trim( parameter1, parameter2 ) as follows:

First parameter can be ignored regardless of it, only need to modify the second parameter.

How to modify the second parameter?
Although I have found three numerical explanations for the second parameter,

but I don’t know how to adjust these three values ?

Re: K32W Xtal

mario_castaneda — Thu, 16 Jul 2020 22:31:58 GMT

Hi Daniel,

Is it possible that you could provide more information/details about your final application?

What is the reason for modifying the trim xtal?

Regards,

Mario

Re: K32W Xtal

danieltseng — Fri, 17 Jul 2020 01:26:57 GMT

Because there is no tool to adjust the frequency,
The current plan can only adjust him directly, and then go to measure it.

The first version of the customer board is coming back, we need to make adjustments in advance.

So we will ask what are the adjustment techniques for these three values?

Re: K32W Xtal

mario_castaneda — Mon, 27 Jul 2020 19:35:48 GMT

Hi Daniel,

What is the load capacitance of 32M crystal that the customer wants to use?

how much frequency offset customer measured on their board?

Usually, we recommend using the 6pf loadcap of 32M crystal on board as there provide internal capacitors(default 6pf) inside K32W. It Is able with suitable external XTAL to meet the required accuracy.

For XTAL calibration, we do not recommend modifying the frequency offset by set this function. The CLOCK_Xtal32M_Trim function is to compensate process spread and temperature changing but not the Xtal tolerance.

Is it possible that you could provide the specification of 32M crystal to review?

Regards,

Mario

Re: K32W Xtal

danieltseng — Thu, 06 Aug 2020 10:26:36 GMT

Dear Mario:

CLOCK_Xtal32M_Trim() function can only be used for temperature compensation.

When K32W has a frequency offset, the hardware solution is the only solution:
1. Hardware solution: can only find other similar 32M crystal to improve the frequency offset.
2. Software solution: cannot modify the software Register ?

Daniel

Re: K32W Xtal

mario_castaneda — Fri, 07 Aug 2020 17:02:31 GMT

Hi Daniel,

Is it possible that you could provide the xtal that you want to use? and we could check and provide any recommendations about the part that you select.

Regards,

Mario

Re: K32W Xtal

danieltseng — Mon, 10 Aug 2020 03:19:20 GMT

Dear Mario:

Thank you for your reply.

At this stage, I mainly want to confirm that when a frequency deviation occurs, the software cannot be modified, only the crystal of the hardware can be modified. I will trouble you if I need help in the future, thank you very much for your reply.

Daniel