9.4 Sense on Reset

Wilink8 has several wake-up options that are entered through sense on reset by three IO's of the device: IRQ_WL, UART_DBG_BT, AUD_OUT_BT.

Once Bluetooth or WLAN enable bit is set to high, the device checks the state of the lines and wakes up in that specific mode.

There are only two modes or configurations that are supported by the device, all of the rest are prohibited and the user must verify that there is no option on the system level to enter the prohibited modes.

The supported modes are:

• Operational mode:
  • IRQ_WL = 0, UART_DBG_BT = 1, AUD_OUT_BT = 0

  Operational mode is set by default using internal pull of WiLink (90K typical).

• Debug mode:

  WLAN RS232 debug interface and Jtag interface are muxed out to the WiLink IO's by default, nevertheless, this mode is only for debug a 10K resistor pull up place holder on the IRQ line should be placed. It can be applied only in case the debug mode is required:

  • IRQ_WL = 1, UART_DBG_BT = 1, AUD_OUT_BT = 0

  NOTE

  In order to avoid an undefined state of the device, be extremely careful when level-shifting those three I/Os to ensure that only those one of the two supported configurations of the device are applied.

  For further details, see Level Shifting WL18xx I/Os (SWRA448).