Wilink8, BT Host wakeup / eHCILL / AM335x deep-sleep

Dav01

Hi,

Seem like TI's firmware uses BT_HCI_RTS in favor to the hard-wired BT_HOST_WAKE_UP pin (BT_FUNC1).

So, that means when a AM335x is in deepsleep0, you only have bank0 gpio or uart0 available as wake-up sources.

Usually (and in our case) the Wilink BT-HCI is connected to the Sitara via the uart3 bus. (I'd say uart0 is buzy for print-outs, boot, etc)

So, question is best way to make this work. A workaround would be to tie BT_HCI_RTS & CTS to separate Hi-Z GPIO's on bank0 that could serve as wake-up sources during AM335x power-down.

Thoughts?

/David

over 11 years ago

0 Dotan Ziv over 11 years ago

TI__Expert 5840 points

Hi David,

Sorry for the late reply.

You will only need to tie the RTS to a seperate Hi-Z GPIO (that can wakeup the AM335x), the controller can wakeup on any UART transaction.

Regards,

Dotan

0 Dav01 over 11 years ago in reply to Dotan Ziv

Expert 2300 points

Hi Dotan,

Yes, we've also connected the RTS to a GPIO Bank_0 pin to allow this.

As the Wifi/BT part is hooked up to UART3 (which is off in deelsleep0), question is if there are any timing requirements when sequencing when the WL18xx signals CTS for150μs up to when the AM335x wakes and releases RTS?

best d

0 Dotan Ziv over 11 years ago in reply to Dav01

TI__Expert 5840 points

Hi,

There are no timing requirements, the controller will wait until the host is awake (and replies to the wakeup request).

Regards,

Dotan

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Wilink8, BT Host wakeup / eHCILL / AM335x deep-sleep