topic Re: Issue: VR5510 request FS0B assertion by FS_SAFE_IOS register in Power Management

Issue: VR5510 request FS0B assertion by FS_SAFE_IOS register

Yang_C — Wed, 12 Mar 2025 09:09:40 GMT

Hi,

I am trying to assert FS0B by writing FS_SAFE_IOS register FS0B_REQ bit. Before doing so, VR5510 has been initialised sucessfully, watchdog is disabled and FS0B is released. Then I use I2C command to write FS0B_REQ to 1, however FS0B is not asserted(still high).

Wondering is there any extra configuration before write this register? The IDE I am using is S32DS3.5.10, LLCE1.0.7, RTD4.0.2.

Looking forward to your reply, thank you.

Kind regards,

Yang

Re: Issue: VR5510 request FS0B assertion by FS_SAFE_IOS register

ErikaC — Wed, 12 Mar 2025 21:26:26 GMT

Hello,

Steps for FS0B release test:

1. Configure the watchdog period WDW_PERIOD [3:0] as 0 to disable
the watchdog.
2. Exit DEBUG mode.
3. The initial value of FLT_ERR_CNT is 1. Feed the dog 6 times and
clear it to 0.
4. Write the complement of WD_SEED to FS_RELEASE_FS0B. If there
is no fault, FS0B can be released at this time.

Please let me know if this works.

Re: Issue: VR5510 request FS0B assertion by FS_SAFE_IOS register

Yang_C — Wed, 12 Mar 2025 22:31:15 GMT

Hi Erika,

Thanks for your reply.

I have already successfully released the FS0B, my issue is I can't do a safety path check by asserting FS0B after VR5510's initialization.

Per VR5510 datasheet, by setting FS_SAFETY_IOS register FS0B_REQ bit to 1, MCU can request a FS0B assertion. I did so, also used oscilloscope to capture FS0B, always high after release. I checked the I2C communication, it works well since I can read the VR5510 deviceID correctly.

Is there any other steps I missed to assert FS0B before sending I2C command?

Re: Issue: VR5510 request FS0B assertion by FS_SAFE_IOS register

Yang_C — Thu, 13 Mar 2025 05:32:50 GMT

Hi Erika,

I did more tests today, realizing I can only read register(Main-0x20, Safety-0x21) correctly. When I tried to write a register and read its value back, the value is not changed. Not sure what happend.

For example, I read M_SM_CTRL1 register, changed the TIMER_STBY_WINDOW[3:0], then read back the register, nothing changed.

Any suggestion?

Re: Issue: VR5510 request FS0B assertion by FS_SAFE_IOS register

ErikaC — Tue, 18 Mar 2025 17:31:04 GMT

Hello, I am checking this with the applications team, I will keep you informed. Thank you for your patience.

Re: Issue: VR5510 request FS0B assertion by FS_SAFE_IOS register

ErikaC — Wed, 19 Mar 2025 22:49:17 GMT

Hello,

If watchdog can be disabled and FS0B release command can be write successfully by I2C to release the FS0B on their board, I think writing register function is OK on your board.

Can you try to write a value to M_MEMORY0 register and read back the value to check if the change can be successful.

What is the full part number you is using ?

Re: Issue: VR5510 request FS0B assertion by FS_SAFE_IOS register

Yang_C — Wed, 19 Mar 2025 22:59:24 GMT

Hi Erika,

Issue is resolved. My mistake, I found I didn't send CRC byte when writing the register.

Thanks for your support.