UCD90160: Clear Logs, Peaks, all flash memory

Hi

1. to clear peak log, you have to write 5 zeros instead of 2 zeros following by a PAGE command first

2. no, you have to erase separated. 

Regards

Yihe

To clear the peak log, I tried running

address 0x00 (page)

address 0xED 0x05 0x00 0x00 0x00 0x00 0x00 (clear peak)

However, do not see the values at 0xED changing. Interestingly enough, I also tried writing to 0xEA with "address + 0xEA + 0x12(length) + eighteen zeros", but the values at 0xEA are not changing either (previously, the write to 0xEA was successful). Do I need to do some sort of write enable first? I'm seeing intermittent write success, and I am trying to figure out how to consistently write to the fault and peak logs.

Hi

 To clear rail 1 peak fault:

address 0x00(page command), 0x00(page index to select rail 1)

address 0xED 0x05 0x00 0x00 0x00 0x00 0x00

Please be noted that, you may have the same peak before and after which is up to your voltage. The test is 

1. let the voltage to higher, to log the peak

2. let the voltage back to normal

3. clear the peak

4. read the peak, it shall have different value if erase is good. 

You have to wait at least 300ms before issuing another erase since it takes time to complete.

Regards

Yihe

I was able to observe the behavior you described. Is there any way to avoid having the peak set immediately after erasing? I would like to read a 0x00 after clearing 0xED to follow non-volatile memory sanitization protocols. 

Hi

No, the peak is updated continuously.

Regards

Yihe

Besides peak and fault logs, is there any other data stored in flash? If so, can it be cleared via pmbus?

Hi

The user configuration data is also stored in the same flash. You do not want to clear it.

Regards

Yihe

What would happen if someone cleared configuration data? Is it possible to do so with pmbus?

Hi

You can enable the security mode to prevent any un-authorized write to protect if this is a concern for you. 

Please refer 10.33 and 10.34

https://www.ti.com/lit/pdf/slvu352 

Regards

Yihe

Ah sorry, I wasn't clear. I am interested in intentionally clearing the configuration data. Is it possible for me to clear the configuration data via pmbus? What would be the consequences of clearing the configuration data?

Great, thanks Yihe, this is what I was looking for.

Will I be able to run

BlockRead,<i2c_addr>,0xE2

BlockRead,<i2c_addr>,0xE3

and have the BlockReads return all zero's after running the commands you describe? I would expect a total 2 Kb of zeros, because the ucd90160 flash is 2 Kb; is this correct?

Also, will these commands put the ucd90160 in an unusable state? I know you mentioned not to perform these steps in normal operation, so I want to understand the consequences.

Hi

For the E2 you have to use write to set the address instead of read.

You will not get all zeros due to the peak log. 

After erase the whole flash, UCD90160 does not perform any function since there is no valid configuration.

your system may not be function since the power rail are not up.

I am not sure why you insist to do this. 

Regards

Yihe

Thank you for your help. I was able to clear the data flash to sanitize the device's non-volatile memory. 

Besides the peak logs, what are the addresses of the remaining data flash memory? I would like to read them and confirm I cleared the data flash. I know I can read the fault logs at 0xEA, but where else is data flash memory addressed?

Hi

Please check section 3.2 of https://www.ti.com/lit/pdf/slua815 to see what are the valid address to read.

Regards

Yihe

I see in section 3.3 that the Data Flash is stored in 0x18800 through 0x19000. However, if I try to run

ReadByte,<addr>,0x18800,0x00

The command fails, because 0x18800 is not a valid address for the ReadByte command. How can I access 0x18800 via ReadByte?

HI 

please read section 10.19 of https://www.ti.com/lit/ug/slvu352g/slvu352g.pdf 

You have to use E2 and E3 command to read. you shall not use absolute address, instead offset shall be used with 0xE2 command.

in order to read 0x18800, please use offset 0.

Regards

Yihe

I was able to successfully read at address 0x18800 with an offset of 0 with the following:

BlockWrite,0x4e,0xE2,0x0200000104
BlockRead,0x4e,0xE3,0xFFFFFFFF

However, then I tried to access the next address by setting offset to 4 to access 0x18804. The write failed  - am I missing something?

BlockWrite,0x4e,0xE2,0x0204000104
BlockRead,0x4e,0xE3,0xFFFFFFFF