TMS320C6742: Confirm the release timing of nRST line at power up.

Kaka

Part Number: TMS320C6742

Hi TI Experts,

We got two questions from my customer. Please provide us your comments.
[Question.1]
Would you please check whether there is any problem for following attached waveform?

Power_sequence.pdf

Note: Other power line like 1.8V and 1.2V has already release before 3.3V line reach to 3.3V.
It seems that this sequence is not problem because the nRST line is released after other power line(3.3V, 1.8V and 1.2V lines). What do you think about this?

[Question.2]
Is there any problem for slew rate of nREST single on the above wave form on attached file? Or does this device has the limitation specification of nRST slew rate?

If you have any questions, please let me know.

Best regards.
Kaka

over 8 years ago

0 Yordan Kovachev over 8 years ago

TI__Guru**** 161600 points

Hi,

I've notified the HW experts. Their feedback will be posted here.

Best Regards,
Yordan

0 Senthilkumar Srinivasan over 8 years ago

TI__Mastermind 43660 points

Kaka,

1. The sequence seems to be fine. May i know why the reset is asserted again at the end ?

2. Please refer section 6.4.3 Reset Electrical Data Timings for RESET requirements.

Regards,
Senthil

0 Kaka over 8 years ago in reply to Senthilkumar Srinivasan

Guru 24520 points

Hi Senthil,

Thank you for your response.

The reason why the reset signal is re-active at the end of waveform is that it was unexpected signal for system. This device controlled by external host device and boot up from this device via HPI. But the host will active at the same time on the C6742. This is why the reset singal was release for a moment.

For your answer No.2, I have already checked this section but I could not find the slew rate specification.
So, does this device have any required slew rate? And is there any problem for my customer's waveform?

Best regards.
Kaka

0 Senthilkumar Srinivasan over 8 years ago in reply to Kaka

TI__Mastermind 43660 points

Kaka,

There is no requirement on the slew rate of the RESET signal. If we want to put an artificial bound on the number if needed (which we still did not put in the datasheet) would be to limit it to 100 msec.

Regards,
Senthil

0 Kaka over 8 years ago in reply to Senthilkumar Srinivasan

Guru 24520 points

Hi Senthil,

Thank you for your quick response.
I will inform this to my customer. If I get more questions, please let me confirm them.

Best regards.
Kaka

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TMS320C6742: Confirm the release timing of nRST line at power up.