We used HCI UART to perform a RAM download from host MCU to CYW20706 according to WICED-HCI-CONTROL-PROTOCAL. After the RAM download, we put 20706 in application mode.
Also, we use Wiced_sleep_config API to put 20706 in low power mode. but we find that 20706 cannot go into low power mode.
As comparison, we test on CYW920706 demo board, and find that 20706 cannot go into low power mode when we open HCI port in Clientcontrol. Even we close HCI in Clientcontrol, it is still not work. 20706 can only go into low power mode with a reset after HCI port open.
Is it a must that HCI UART disabled to go into low power mode? As our board has no serial flash, what could we do to let it in low power mode after RAM download?
Basically, if the HCI UART CTS is pulled low during reset, then the device won't enter low power. Even if the UART is open(CTS released) afterwards, the device still won't enter low power mode.
I am afraid there is no workaround as of now if you performing a RAM download.