Regarding PSoC4S Self Test of CapSense_TST_SNS2SNS_SHORT

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YuMa_1534086
Level 7
Level 7
Distributor - Macnica (Japan)
500 replies posted 250 sign-ins 10 likes received

Hello Cypress.

Q1)

Customer says that test result of Self Test of CapSense_TST_SNS2SNS_SHORT changes depending on CapSense component version.

In 4.0 version, test result becomes pass.

But test result becomes fail at 6.0.

(Conditions other than CapSense Version does not change.)

Is there possibility that test result changes depending on CapSense version?

Has test procedure changed in V4.0 and V6.0?

Or is test procedure of V4.0 and V6.0 same?

Q2)

Below is description of CapSense component DS.

DS explains about adding VDDA test to Self Test.

Could you please let us know changes in Self Test other than below.

Customers would like to know what has changed from V4.0 to V6.0.

They think that there may be minor changes other than below because short test result changes depending on version.

pastedImage_5.png

Best Regards.

Yutaka Matsubara

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1 Solution

Hello Matsubara-san,

CapSense_ExecuteSns2SnsShortExt() has been modified.

If you look at the function definition in CapSense V4, you can see that in case of ganged sensors, first all the pins with respect to it are set to pull-up drive mode and then we read all the sensor states to check if any sensor pin state reads '0'.

Since all the pins are high, a sensor to sensor short (pin short) with the ganged sensor could not be identified this way. This bug has been fixed in the next revision (CapSense V5).

I assume the customer is using ganged sensors. Pls ensure that the different ganged sensors are not shorted together.

Thanks,
Shanmathi

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9 Replies
ShanmathiN_06
Employee
Employee
100 replies posted 50 replies posted 25 replies posted

Hello Matsubara-san,

1) Yes, the testing of Sensor to Sensor short has been updated in CapSense V5.

So, the test result is accurate in versions above CapSense V5

2) I assume you would like to know if there are any other changes in Self test procedure. I will check this internally and update ASAP.

Thanks,
Shanmathi

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Hello Matsubara-san,

The following are the changes from V4 to V6:

1. CheckSensorShort(),  MeasureExtCapCapacitance() has been modified

2. Minor changes to include CSD and CSX mode

Other than the above-mentioned changes, the overall functionality remains the same

However, when you update from one component version to another, it is always recommended to validate the firmware.

Thanks,
Shanmathi

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YuMa_1534086
Level 7
Level 7
Distributor - Macnica (Japan)
500 replies posted 250 sign-ins 10 likes received

Hello Shanmathi-san.

Q1)

CheckSensorShort(short to GND or VDD) has been modified.

But CapSense_TST_SNS2SNS_SHORT(short to other sensors) has not changed at all.

Is my understanding correct?

Q2)

I did not understand the meaning of the following contents well.

What does that mean?

===================================

Minor changes to include CSD and CSX mode

===================================

Best Regards.

Yutaka Matsubara

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Hello Matsubara-san,

1) In addition to sensor to sensor short, sensor short (to Vdd/gnd) and external capacitance measurement tests has been modified.

So, in the customer's board, sensor was shorted to another sensor, resulting in fail scenario when CapSense V6 was used.

2) APIs has been modified with #if condition checks to perform test procedure for CSD and CSX sensing individually. (i.e) If CSX sensing method is enabled, a different macro is enabled, which results in the execution of firmware that is written exclusively for CSX mode.

Ideally, this should not cause any major functionality change in the test procedure.

Thanks,
Shanmathi

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YuMa_1534086
Level 7
Level 7
Distributor - Macnica (Japan)
500 replies posted 250 sign-ins 10 likes received

Hello Shanmathi-san.

Could you please let us know a difference of sensor to sensor short test procedure between V4.0 and V6.0?

And could you please let us know why test result changes between V4.0 and V6.0?

Best Regards.

Yutaka Matsubara

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Hello Matsubara-san,

CapSense_ExecuteSns2SnsShortExt() has been modified.

If you look at the function definition in CapSense V4, you can see that in case of ganged sensors, first all the pins with respect to it are set to pull-up drive mode and then we read all the sensor states to check if any sensor pin state reads '0'.

Since all the pins are high, a sensor to sensor short (pin short) with the ganged sensor could not be identified this way. This bug has been fixed in the next revision (CapSense V5).

I assume the customer is using ganged sensors. Pls ensure that the different ganged sensors are not shorted together.

Thanks,
Shanmathi

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YuMa_1534086
Level 7
Level 7
Distributor - Macnica (Japan)
500 replies posted 250 sign-ins 10 likes received

Hello Shanmathi-san.

Thank you for your answer.

I confirm whether customer uses ganged sensors or not.

Best Regards.

Yutaka Matsubara

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Hello Matsubara-san,

Did you confirm with the customer?

Thanks,
Shanmathi

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YuMa_1534086
Level 7
Level 7
Distributor - Macnica (Japan)
500 replies posted 250 sign-ins 10 likes received

Hello Shanmathi-san.

I have not received reply from customer yet.

So I would like to close this discuss once.

Best Regards.

Yutaka Matsubara

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