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gunasekart
Level 2
Level 2
10 replies posted 5 replies posted 10 sign-ins

Hi Team,

am using the TC333 controller, I want to implement the RTC in our project. Need to know the hardware connection where battery has to be connect.

am not seen any information's about RTC in datasheet.

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1 Solution
cwunder
Employee
Employee
5 likes given 50 likes received 50 solutions authored

Just to add some more comments to using the SCR RTC. The SCR on the AURIX needs to be configured and started after a "cold" power on reset. The SCR memory needs to be loaded from flash by somebody other than the SCR itself as it can’t access the SPB. That means a master (CPU or DMA) must load it from the PFlash and start the SCR. Once this is done then the SCR RTC can run. As already stated the SCR is powered from the VEVRSB power domain.  You would need to check your current draw calculations for using a coin cell battery but another requirement is that the VEXT and VEVRSB be at the same voltage potential. Using a 3V coin battery you would also need the VEXT to be at the voltage range (until you go into Standby mode). I would think your power scheme would switch in the coin cell battery on the VEVRSB supply rail (i.e. when you turn off the other supplies by going into Standby mode on AURIX, keeping only VEVRSB powered).

The SCR RTC can run from the internal 70kHz clock, or PCLK, or from a clock on P33.10. You also have to consider how to wake-up the system. The AURIX cannot wake until the VEXT voltage returns; generally, you will need a pin from the SCR to enable your main supply if your wake event is only the RTC.

There is also a wake up timer (WUT) on the AURIX that that can also be used however you would need keep VEXT powered as there is not a way to bring the AURIX out of standby when VEXT is not powered.

Another note is the 70kHz clock is not very accurate and is not trimmed by the SSW. You would need to do this yourself if you want any accuracy.

You can also make your own 32.768kHz clock for P33.10 using a 32.768kHz crystal and CMOS inverter (SN74LVC2GU04) with some caps and resistors.

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14 Replies
Jeremy_Z
Moderator
Moderator
Moderator
1000 replies posted 250 sign-ins 100 likes received

Hi @gunasekart 
Actually, I'm not very clear with your goal, as there's no particular RTC (Real Time Clock) module in the TC3xx, so I was wondering if you could describe your question again.
BR,
Jeremy

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TBencher
Level 6
Level 6
25 solutions authored 25 likes received 5 questions asked

Hi Jeremy,
hi  gunasekart,

maybe he/she wants to use the Standby Controller (SCR) where an RTC is included. Here you need of course to power up the Standby Domain separately. If I am not wrong there could be some shared ADC-PADs which you could utilize for it.

Best,

TBencher

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gunasekart
Level 2
Level 2
10 replies posted 5 replies posted 10 sign-ins

Hi Team,

Thanks for response. Actually, I want to connect the Battery to TC33X controller to enable/configure the RTC in controller. We need to confirm is it possible with this controller or pls suggest any other way.

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TBencher
Level 6
Level 6
25 solutions authored 25 likes received 5 questions asked

Hi,

as Jeremy already pointed out, there is no RTC by default available. But, if you want to utilize the Standby Controller, then you would have one inside of it. What are you planning to do? Please describe your application. 

Best,

TBencher

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gunasekart
Level 2
Level 2
10 replies posted 5 replies posted 10 sign-ins

We want to adding a coin-cell (battery) to power the on-board Real-Time-Clock on the TC333

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TBencher
Level 6
Level 6
25 solutions authored 25 likes received 5 questions asked

Hi,

ok, but we would need a bit more information. What should your RTC be responsible for? Are you aware of what we already tried to explain you?

Best,

TBencher

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gunasekart
Level 2
Level 2
10 replies posted 5 replies posted 10 sign-ins

Hi,

I under that TC33X doesn't have inbuilt RTC. Is it correct?. But in specification below mentioned Real Time Clock is Yes.  That is the reason we requested how to use this one. 

Our application is RTC shall run (by connecting coin cell ) even the module power is OFF . In Hardware what power pin for standby controller which included RTC and how to use of it. Could you please provide the any manual and section where it explained.

SAK-TC333LP-32F300F AA - Infineon Technologies

 

gunasekart_0-1693451270378.png

 

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Jeremy_Z
Moderator
Moderator
Moderator
1000 replies posted 250 sign-ins 100 likes received

Dear @gunasekart 
The Real-time clock is a sub-module in the SCR, please refer to 49.11 Real-Time Clock (RTC) in the TC3xx's user manual.
BR,
Jeremy

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Hi Jeremy,

Thanks for response. I understand that RTC is sub-module of SCR. My query is hardware connections where (which MCU pin) I have to connect the coin cell. Is there any hardware manual/application of RTC testing also whether external RTC clock is required.

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TBencher
Level 6
Level 6
25 solutions authored 25 likes received 5 questions asked

Hi,

unfortunately I am a bit more busy today but I'll check that later.

 

Best,

TBencher

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TBencher
Level 6
Level 6
25 solutions authored 25 likes received 5 questions asked

Hi,

the PINs to power up the SCR depend on your package and are called VEVRSB:

1. T11 for LFBGA-292
2. H9 for LFBGA-180
3. 52 for TQFP-144
4. 39 for TQFP-100
5. 28 for TQFP-80

No dedicated example code available, unfortunately.

Best,

TBencher

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Hi,

Thanks for quick response.

1.We need to know whether external RTC clock is required or while powered ON this pin MCU will generate internal clock to RTC. Also confirm whether we can connect the Battery (coin cell) to this pin. Suggested any circuit?

2. But initially mentioned RTC module does not present in MCU. any specific reason?

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TBencher
Level 6
Level 6
25 solutions authored 25 likes received 5 questions asked

Hi,

to answer this question we would need to know a little bit more about your application. But, in general you could connect any DC source as long as the given electrical requirements are fulfilled. You should also consider having a monitoring mechanism in case your voltage comes close to the required minimum voltage. Usually, if your application is somehow safety relevant, I would suggest you to use the TLF35584 where you also have monitoring functionality included. Unfortunately, we cannot suggest any circuitry for free, but if you take a Triboard for example, you would find those things in the included schematics. Your second question, well everything is physically in one package. The reason why the RTC is only available inside the SRC could be its independence from everything else. I did not make the decision, but maybe someone from IFX can explain it better.

Best,

TBencher

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cwunder
Employee
Employee
5 likes given 50 likes received 50 solutions authored

Just to add some more comments to using the SCR RTC. The SCR on the AURIX needs to be configured and started after a "cold" power on reset. The SCR memory needs to be loaded from flash by somebody other than the SCR itself as it can’t access the SPB. That means a master (CPU or DMA) must load it from the PFlash and start the SCR. Once this is done then the SCR RTC can run. As already stated the SCR is powered from the VEVRSB power domain.  You would need to check your current draw calculations for using a coin cell battery but another requirement is that the VEXT and VEVRSB be at the same voltage potential. Using a 3V coin battery you would also need the VEXT to be at the voltage range (until you go into Standby mode). I would think your power scheme would switch in the coin cell battery on the VEVRSB supply rail (i.e. when you turn off the other supplies by going into Standby mode on AURIX, keeping only VEVRSB powered).

The SCR RTC can run from the internal 70kHz clock, or PCLK, or from a clock on P33.10. You also have to consider how to wake-up the system. The AURIX cannot wake until the VEXT voltage returns; generally, you will need a pin from the SCR to enable your main supply if your wake event is only the RTC.

There is also a wake up timer (WUT) on the AURIX that that can also be used however you would need keep VEXT powered as there is not a way to bring the AURIX out of standby when VEXT is not powered.

Another note is the 70kHz clock is not very accurate and is not trimmed by the SSW. You would need to do this yourself if you want any accuracy.

You can also make your own 32.768kHz clock for P33.10 using a 32.768kHz crystal and CMOS inverter (SN74LVC2GU04) with some caps and resistors.