FS26 is abnormally awakened after entering the LPOFF mode

[liyongfeng]

After the MCU sends the LPOFF power off command, FS26 occasionally restarts without a wake-up source after completing the power off operation. By reading the M-WIO-FLG register: WUEVENT=1111, all event flags are 0. The waveform of VSUP shows that it has been maintaining normal 12V without any abnormal conditions.
I would like to ask: What is the reason for FS26 being awakened by WUEVENT=1111 while VSUP remains normal?

[TomasVaverka]

Hi,

WUEVENT=1111 means a VSUP lost and Main state machine is reset. It is cannot be understable that device will be wakeup automictically, can you share test result of Vsup, Vpre, Wake pins and SPI signals to check what make the difference?

BRs, Tomas

[liyongfeng]

[liyongfeng]

[TomasVaverka]

Hi,

FS26 has many wakeup sources, like WAKE1, WAKE2, GPIO1, GPIO2 and SPI, can you please check if all the wakeup sources are not available when sending LPOFF command?

In another side, 2 SPI commands should be sent within 10ms so that the device enter LPOFF mode, is it possible to check if your SPI commands meet this requirement?

BRs, Tomas

[liyongfeng]

The driver software version I am using is the FS26 SBC AUTOSAR 4.4 Version 1.0.0 CD01 for NXP. The wake source only enables wake1. After sending the SPI command from the waveform, FS26 pulls down the RSTB and FS0B signals. Not abnormal wake up every time, M-WIO-FLG register value at normal wake up: WUEVENT=0001, WAKE 1 _ FLAG = 1;

[TomasVaverka]

Hi,

I was informed that you are in touch with our local application engineer supporting the FS26. Therefore I will let him to follow up on this to not duplicate the effort. 

BRs, Tomas

[liyongfeng]

I write 02h to the register M_MEMORY0 and then send the LPOFF command; Then FS26 self wakes up(no wake-up source), the value of the register in M_MEMORY0 becomes 0, and at the same time, the WUENENT of the register in WIO-FLG is 1111. I believe that a POR-M event has occurred, and I have detected that VSUP is at normal 12V. I would like to know what event will cause the main state machine to perform a reset operation?