Sbc FS26 standby mode

[a_dobrik]

Hi !
I have a troubles with using SBC FS26 + S32K3xx.

I want to make wake up for Sbc by using WAKE1 source (I had add bit in WIO_CFG).

After power on I have achieved (from Debug mode - WDG is disabled) Normal mode with released FS1B and FS0B with using this command sequence:

1. Close INIT FS state with 1 good WDG refresh

2. Made WD_ERR_LIMIT good WDG refreshes (6 by default)

3. EXIT Debug mode

4. Release FS0B and FS1B.

After this I've read FS_STATES register and fail state system of Sbc is in Noramal mode (01011).

So, I want to go to Sbc Standby mode and download to Sbc commands (to LQ_REQ register) 0xAA and 0x55. Sbc goes to undefined condition (full power off) and doesn't wake up from WAKE1.

Also I have tryed to use M_REG_CTRL1 and M_REG_CTRL2 for disable for example LDO1 or LDO2, but result is the same - device doesn't wake up from WAKE1....

Maybe I can't understand something in wake up configuration?

[TomasVaverka]

Hi Alexander,

First off, I suppose you have the AN12995 (FS26 Product Guidelines) which provides the following information about entering the Standby mode.

Based on your description, it seems that you are doing everything right, jus two points to double check:

1. Is the delay between the two commands 0xAA and 0x55 less than 10ms?
2. Did you set WK1WUEN bit in the M_WIO_CFG register before sending the two commands above?

Best regards,

Tomas

[a_dobrik]

Hi) Thank's for response.
Maybe I have found error - is was connected with incorrect voltage on DEBUG pin of SBC after reset.
It was more then +6V, so maybe the chip goes to OTP mode instead of waking up. Right now, with +0V on Debug pin it is work (waking up with WAKE 1).
I have another questions for you:
1. Sleep mode (with 0xA5, 0x5A sequence) works right now, but if I want to use Standby mode
can I configure CTRL1 and CTRL2 registers before switching (before sequence 0x), for example if I want
to use Vcore or Vref in Standby mode?
2. If power sources in Standby mode can be configured only with OTP mode, what is the purpose of M_REG_CTRL1 and M_REG_CTRL2 registers?

[TomasVaverka · Accepted solution]

Hi Alexander,

When the device is in Standby mode, VPRE remains enabled and LDO1/LDO2 activation is selectable via OTP configuration as shown below. In most cases, LDO1 or LDO2 regulators are used in Standby mode to supply light loads.

When the device is in LPOFF mode, all the regulators are turned off.

Using the bits in M_REG_CTRL1 and M_REG_CTRL2 registers, you can enable/disable the regulators in Normal mode.

Best regards,

Tomas

[Akhil1]

Hello @TomasVaverka , Can you please provide any example file of SBC FS26 wakeup using LDT in S32k3 controller.

Regards 

Akhil

[a_dobrik]

Hi ! Thank's for help.
Also question connected with Fail-State system:
Am I correct that if I will change M_REG_CTRL1 and M_REG_CTRL2 in Normal mode with active Fail-State system (for example I decide to disable TRK1), I must use SPI command "GOTO_INIT" for switching to INIT FS and restart Fail-State system initialiyation.
Or if one of the power sources inside Sbc (for example TRK1) is disabled I can't achieve Normal mode with active Fail-State system?