ADSP-SC5xx/ADSP-215xx

Q&A is it ok to have a different frequency (other than 24MHz) at USB CLKIN pin at power up?

ADSP-SC5xx/ADSP-215xx requires membership for participation - click to join

State Verified Answer
+2 person also asked this people also asked this
Replies 4 replies
Subscribers 39 subscribers
Views 1723 views
Users 0 members are here

Options

Related

is it ok to have a different frequency (other than 24MHz) at USB CLKIN pin at power up?

tarangjindal on Oct 8, 2018

Hello,

In our application, at power up, the clock device will provide around 80MHz clock to USB CLKIN pin instead of 24MHz.

After power up, ADSP-SC587 will program the clock device to have 24MHz clock to provide to USB CLKIN pin.

so, is it safe to provide a frequency other than 24MHz to USB CLKIN pin for a short duartion after power up?

Thanks and Regards

Tarang Jindal

Top Replies

Jithul_Janardhanan
Oct 28, 2018 +1 verified
Hi Tarang,

As mentioned in the datasheet of ADSP-SC58x, the USB frequency should not minimum or maximum 24MHz. Please refer datasheet of ADSP-SC58x below,

http://www.analog.com/media/en/technical-documentation…
Jithul_Janardhanan
Dec 14, 2018 in reply to havran +1 verified
There is no specific power up sequence required if the board which is having a 22k or stronger Pull-down on TWRST and SYS_HWRST pin.

+1 Jithul_Janardhanan

on Oct 28, 2018 6:56 PM over 2 years ago
Hi Tarang,

As mentioned in the datasheet of ADSP-SC58x, the USB frequency should not minimum or maximum 24MHz. Please refer datasheet of ADSP-SC58x below,

http://www.analog.com/media/en/technical-documentation/data-sheets/ADSP-SC582_583_584_587_589_ADSP-21583_584_587.pdf

Best Reagrds,

Jithul
Cancel
Up +1 Down

Reply

Reject Answer

Cancel
0 havran on Dec 10, 2018 6:28 PM over 2 years ago in reply to Jithul_Janardhanan

Hello,

from that datasheet it is unclear to me if it is required to have 24 MHz at the power up, or just before enabling USB is enough (like enabling the USB PHY by setting the USB_PHY_CTL.EN bit).

Regards,

Jan
Cancel
Up 0 Down

Reply

Verify Answer

Cancel
+1 Jithul_Janardhanan

on Dec 14, 2018 6:56 AM over 2 years ago in reply to havran
There is no specific power up sequence required if the board which is having a 22k or stronger Pull-down on TWRST and SYS_HWRST pin.
Cancel
Up +1 Down

Reply

Reject Answer

Cancel
0 havran on Jan 25, 2019 6:10 PM over 2 years ago in reply to Jithul_Janardhanan

Hello,

to clarify my question, is USB clock required to be valid (24MHz) immediately when SC5xx is released from reset or can it be set to 24MHz a bit later (say 100ms) and a long enough before software USB initialization?

Thank you,

Jan
Cancel
Up 0 Down

Reply

Verify Answer

Cancel