AM3352: Inquiry about bootup-time from de-asserted PWRONRSTn

Takayuki Miyazaki

Part Number: AM3352
Other Parts Discussed in Thread: TPS650250

Hello team,

Our customer is developing the next generation system with AM3352BZCZ60.

Is there a specification/datasheet definition for the time from when PWRONRSTn goes Low->high to starting to access to the Boot-Device (SPI0)?

As the SPI-Flash’s requirement, there seem to be limitation for this time, and customer would like to confirm it. Customer tried to verify it, and they confirmed this time is around 47usec. Since this requirement is more than 16msec, there is not any problem. If TI has any data/definition for this, would you share this information, please?

It will be appreciated if you will share expert’s advice/comment on this inquiry.

Best regard,

Miyazaki

over 2 years ago

0 Kallikuppa Sreenivasa over 2 years ago

TI__Guru**** 197129 points

Hello Miyazaki

Thank you for the query.

Please refer the below provided in the datasheet.

The below FAQ has the link to all the key collaterals including the datasheet.

https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1189177/faq-am3351-am3352-am3354-am3356-am3357-am3358-am3359-custom-board-design-collaterals-to-get-started?tisearch=e2e-sitesearch&keymatch=faq%3Atrue

Here are my inputs

Boot Modes – Boot Mode is Selected Through Boot Configuration Pins Latched on the Rising Edge of the PWRONRSTn Reset Input Pin

I am checking with the experts if the WARMRSTn, nRESETIN_OUT output can be used an a quick indication for the start of the boot.

Regards,

Sreenivasa

+1 Kallikuppa Sreenivasa over 2 years ago in reply to Kallikuppa Sreenivasa

TI__Guru**** 197129 points

Hello Miyazaki

Additionally, Pls refer below additional inputs i received from the expert.

WARMRST can be used as a general guide on when the ROM start executing on AM335x, but it won’t be exact.

If you check figures 8-26 or 8-27 in the TRM, for example, you will see there is some time for the reset to propagate thru the device after warm reset goes high. Only after this time will the ROM begin execution. This time is not defined in AM335x.

I guess I’m confused by the customer’s original question.

Pls help understand wat is the exact limitation of the SPI flash customer is worried about?

Regards,

Sreenivasa

0 Takayuki Miyazaki over 2 years ago in reply to Kallikuppa Sreenivasa

TI__Genius 10120 points

Hi Sreenivasa,

Thank you for your comments.

I'll request customer to refer figures 8-26 or 8-27 in the TRM. and, since there is some time for the reset to propagate thru the device after warm reset goes high, I'll inform this time is not defined in AM335x.

And I'll ask customer what is the exact limitation of the SPI flash customer worried about.

Best regards,

Miyazaki

0 Kallikuppa Sreenivasa over 2 years ago in reply to Takayuki Miyazaki

TI__Guru**** 197129 points

Hello Miyazaki

Thank you for the note.

Regards,

Sreenivasa

0 Takayuki Miyazaki over 2 years ago in reply to Kallikuppa Sreenivasa

TI__Genius 10120 points

Regarding the limitation of SPI Flash customer is using, I received customer’s feedback.

It seems it needs take 16ms(min) from power-on until it becomes accessible. Customer is using TPS650250 PMIC device, and TPS650250’s PWRFAIL pin is connected to AM3352’s PWRONRSTn pin in customer’s circuit. Also, it takes 4ms until PWRONRSTn goes High after Power-on. This is reason why customer was asking if there is definition for this.

I’d like to close this ticket because I had shared your comments.

Thank you for your clarification.

Best regards,

Miyazaki

0 Kallikuppa Sreenivasa over 2 years ago in reply to Takayuki Miyazaki

TI__Guru**** 197129 points

Hello Miyazaki

Thank you for the inputs.

Regards,

Sreenivasa

0 Takayuki Miyazaki over 2 years ago in reply to Kallikuppa Sreenivasa

TI__Genius 10120 points

Hi Sreenivasa,

I received one question from customer just now.
Since This time is not defined in AM335x, this means TI is not able to guarantee this time is more than 16ms. Is that correct?

I believe so, but, I need expert's comments.

I appreciate your advice.

Best regards,

Miyazaki

0 Kallikuppa Sreenivasa over 2 years ago in reply to Takayuki Miyazaki

TI__Guru**** 197129 points

Hello Miyazaki

Thank you for the additional query.

Your understanding is correct.

Regards,

Sreenivasa

0 Takayuki Miyazaki over 2 years ago in reply to Kallikuppa Sreenivasa

TI__Genius 10120 points

Hi Sreenivasa,

Thank you so much for your comment.

Best regards,

Miyazaki

0 Kallikuppa Sreenivasa over 2 years ago in reply to Takayuki Miyazaki

TI__Guru**** 197129 points

Hello Miyazaki

Thank you for the note.

Have a great day.

Regards,

Sreenivasa

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AM3352: Inquiry about bootup-time from de-asserted PWRONRSTn