KITVR5510DA0EVM Exit Standby

[jiaweilin]

Hello,

I am using KITVR5510DA0EVM to test the Standby mode transition function.

When I tried to exit the Standby mode by "STBY pin = Low", VR5510 did not re-enter the Normal_M mode as expected, but a reset occurred. It looks as if the PGOOD and RSTB could not be released due to the VCOREMON_OV occurrence, making 8sTimer time out, thus entering Deep-FS and causing reset.

Is there any wrong I have do or any step I have miss?

operation is as follows:

1. Load and run the test script according to UM11587-8.1 Operating in debug mode;
2. Disable M_SM_CTRL1[STBY_TIMER_EN]；
3. Entry Standby Mode: Set STBY pin = High；
4. Check STBY_PG=Low；
5. Exit Standby Mode: Set STBY pin = Low.

The phenomenon is as follows:

After exit Debug Mode:

1. M_MODE[MAIN_NORMAL] = High;
2. FS_STATES[FSM_STATE]=NORMAL _FS;
3. PGOOD、RSTB、FS0B Released;
4. The OTP configuration read out through the MIRROR window is consistent with the TBB script.

After Step 3:

1. FS0B asserted.

After Step 5:

1. In ACCESS - Diag Safety - OV/UV status window: VCOREMON_OV and  VCOREMON_UV asserted；
2. PGOOD、RSTB、FS0B asserted；
3. KITVR5510DA0EVM reset after 8s；
4. The OTP configuration read out through the MIRROR window is not consistent with the TBB script.

Looking forward to your reply.

Thank you very much!

*PS:Attached are the TBB script file I used and the OTP configuration file read out through the MIRROR window after reset.

[JozefKozon]

Dear Weilin,

please refer the section 23.8.4 in the VR5510 datasheet. To release the FS0B you need to fulfill three conditions. By default the Fault Error Counter is set to 1, you need to decrease it to 0 with a good watchdog refresh. And only after that release the FS0B. Otherwise the FS0B will be asserted again.

With Best Regards,

Jozef

[jiaweilin]

Thank you for your reply.

Before I set STBY pin=Low to make VR5510 enter the Standby mode, I have made the Main&Fail-safe state machines of VR5510 in Normal mode. At this time, PGOOD, RSTB, FS0B are released, and FLT_ERR_CNT is 0.

After I set STBY pin=Low to put VR5510 into Standby mode, FS0B is asserted again (FS0B=Low).

I have two questions:

1. Is the failure to exit Standby mode related to FS0B being LOW? Is it necessary to release FS0B before exiting Standby mode? According to "AN12880-5.8 Functional safety during Standby mode", I understand that FS0B remains Low in Standby mode.
2. How do I clear the fault count and release FS0B in Standby mode? After VR5510 enters Standby mode, in NXP GUI-ACCESS-Diag Safety-WatchDog Management window, I see WD_ERR_CNT=0xf, WD_RFR_CNT=7, FLT_ERR_CNT=0xf, and I try to send a "Good Watchdog refresh" to clear the fault count, but nothing happens.

Expect your reply.

Thank you  very much.

[JozefKozon]

Dear Weilin,

1. Is the failure to exit Standby mode related to FS0B being LOW? Is it necessary to release FS0B before exiting Standby mode? According to "AN12880-5.8 Functional safety during Standby mode", I understand that FS0B remains Low in Standby mode.
2. How do I clear the fault count and release FS0B in Standby mode? After VR5510 enters Standby mode, in NXP GUI-ACCESS-Diag Safety-WatchDog Management window, I see WD_ERR_CNT=0xf, WD_RFR_CNT=7, FLT_ERR_CNT=0xf, and I try to send a "Good Watchdog refresh" to clear the fault count, but nothing happens.

[A] This looks, that one of the BIST hasn't been done successfully after wake up from Standby. If either LBIST or ABIST1 fail, the RSTB and PGOOD are released, but FS0B remains stuck low and cannot be released. Please refer to the sections 23.9.1 and 23.9.2 in the VR5510 datasheet. Please check if the LBIST and ABIST1 have passed, by checking the ABIST1_OK and LBIST_PASS bits in the FS_DIAG_SAFETY register.

With Best Regards,

Jozef

[jiaweilin]

Thank you for your reply.

I checked the register FS_DIAG_SAFETY after exiting standby mode.

As you said, LBIST passed, but ABIST1 failed.In addition, VCOREMON_OV and VCOREMON_UV are asserted.

I have two questions.

1. I compared the OTP configuration that read through the "NXP GUI-MIRROR-Mirrors OTP Export".I found that the Fail-safe part of the OTP configuration was inconsistent (Read OTP configuration in Normal & Read OTP configuration after exit Standby). For example, the VCORE monitoring voltage changes from 0.8V to 0.53750V, that is, after entering or exiting the Standby mode, the Fail-safe part of the OTP configuration is modified. Why does this happen?
2. Whether the PGOOD and RSTB cannot be released due to the occurrence of VCOREMON_OV, causing the 8sTimer timeout reset VR551?

Expect your reply.

Thank you  very much.

[JozefKozon]

Dear Weilin,

1. I compared the OTP configuration that read through the "NXP GUI-MIRROR-Mirrors OTP Export".I found that the Fail-safe part of the OTP configuration was inconsistent (Read OTP configuration in Normal & Read OTP configuration after exit Standby). For example, the VCORE monitoring voltage changes from 0.8V to 0.53750V, that is, after entering or exiting the Standby mode, the Fail-safe part of the OTP configuration is modified. Why does this happen?

[A] If the STBY timer expires the VR5510 goes to OFF mode and you need to load the fuses again with the requested data. You have the non-programmed version. Please refer to the Figure 4. in the VR5510 datasheet. 

2. Whether the PGOOD and RSTB cannot be released due to the occurrence of VCOREMON_OV, causing the 8sTimer timeout reset VR5510?

[A] You can set the impact of the VCOREMON_OV by setting the VCOREMON_OV_FS_IMPACT bits in the FS_I_OVUV_SAFE_REACTION1 register. By default the VCOREMON_OV_FS_IMPACT bits are set to assert the FS0B and RSTB pins. If you have left it to default, then yes, the VCORE overvoltage will assert the RSTB pin. Impact on the PGOOD due to VCOREMON overvoltage must be defined in the OTP. In the RSTB2PGOOD_OTP bit. Please refer to the section 23.7.2, page 80.

With Best Regards,

Jozef

[jiaweilin]

Thank you for your reply.

I refer to Figure 23 of AN12880 to verify the exit Standby. I disable M_SM_CTRL1[STBY_TIMER_EN].

In this case, the STBY timer should not expire, right?

Do I need to load the fuses again with the requested data after I exit the Standby mode by STBY wake up (STBY pin) command?

Expect your reply.

Thank you  very much.

[JozefKozon · Accepted solution]

Hello Weilin,

please see below answers from an application engineer I have contacted.

DESCRIPTION

Q1:I refer to Figure 23 of AN12880 to verify the exit Standby. I disable M_SM_CTRL1[STBY_TIMER_EN].

In this case, the STBY timer should not expire, right?

A1: Correct. 

Q2: Do I need to load the fuses again with the requested data after I exit the Standby mode by STBY wake up (STBY pin) command?

A2: Customer needs to program(burn) OTP to a VR5510 part to try the standby entry and exit functions but not using the TBB mode. If they use a programmed part, the device will automatically load burned OTP when it exits standby mode. 

With Best Regards,

Jozef

[jiaweilin]

Thank you for your reply.

About OTP (one-time programmable) configuration.

Whether the OTP register can be programmed only once.

Whether the value of the OTP register can no longer be modified after the OTP register is burned successfully, even if the power is repowered and the Debug mode is entered.

Expect your reply.

Thank you very much.