MCU Deep Sleep enabling USB host function.

[JuMo_1762556]

I am trying to let CYW43907 (WICED-Studio-6.1) sleep during enabling USB host function.

I uses test sample program, <WICED_Studio>/apps/test/powersave/powersave.c.

To make MCU in DeepSleep mode, I called wiced_usb_host_init in this sample program, but it doesn't go to DeepSleep mode.

When execute mcu_powersave_sleep 1 3000, "Refuse to sleep due to WLAN resources are still requested" is displayed and doesn't go to sleep.

Does anyone have any suggestion for this issue ?

Or CYW43907 can't go to DeepSleep mode when enabling USB host ?

[JuMo_1762556]

Does anyone have comment for my question ?

[MichaelF_56]

Adding a few members of the Applications team: grsr riya rroy zhez zhxh yans kavs shjl

[PriyaM_16]

43907 can not go to deepsleep in USB host mode as the USB stack is using the resources. In deep sleep mode, all the clocks except the 32KHz are powered down. Hence the clock to the USB core is powered down. In such case the USB core can not be initialized.

[JuMo_1762556]

Can I go to Deep Sleep after USB is disabled ?

When I tried to go to Deep Sleep without enabling/disabling USB, the current drops about 30mA.

(I didn't do anything about USB in this case.)

But when I tried to go to Deep Sleep after enabling and disabling USB, the current drops only 10mA.

Does anyone know why this difference is happened ?