Requirement for USB suspend

Ichiro Fukui

Hi,

Our customer has a application to use C5504 for their products. They would like to understand the requirement (or guideline) of register setting for USB suspend.

When both C5504 and USB host has suspended (i.e. Only VBUS is provided and others are suspended), is there any recommended setting for power related register and 1.5K ohm internal pull-up (for both DP and DM line) resistor?

Thanks in advance.

regards,
Fukui

over 12 years ago

0 David (ASIC) Liu over 12 years ago

TI__Guru**** 178226 points

Fukui

Is this a USB bus-powered or a USB self-powered application?

To enter into suspend, you need to set both ENSUSPM and SUSPENDM bit in Power Management Register. The 1.5k internal resistor gets automatically pulled up.

Thanks

David

0 Ichiro Fukui over 12 years ago in reply to David (ASIC) Liu

TI__Intellectual 1310 points

Hi David,

Thanks for your reply.

This is an USB bus-powered device. I understand that setting both ENSUSPM and SUSPENDM register controlls internal resistor. Do we have recommend setting for other registers to entre suspend mode?

Our customer just wants to confirm if there are any recommendation.

regards,
Fukui

0 David (ASIC) Liu over 11 years ago in reply to Ichiro Fukui

TI__Guru**** 178226 points

Fukui-san

Setting both ENSUSPM and SUSPENDM bits will put C5504 into USB suspend mode. For bus-powered application, do they also care that they have to meet USB suspend current requirement?

Thanks

David

0 Ichiro Fukui over 11 years ago in reply to David (ASIC) Liu

TI__Intellectual 1310 points

David,

Thank you. I understand setting ENSUSPM and SUSPENDM bits are enough.

Regarding USB syspend current requirement, customer willing to have it. We've discussion and I think that tyey don't care USB suspend current requirement now.

regards,
Fukui

Processors

Processors forum

Requirement for USB suspend