FlexRAM clean up method and margins?

[JeorgeB]

Hi, I use S32k144 in my project and want to use FlexRAM as emulated Eeprom.

1. when I want to run quick write mode, maximum time for clean up is (#number of quick writes * 2) ms. is this true: "when we want to write 32 bytes, clean up time will be : (32/4)*2 = 16 ms at maximum" ?

2. what is mean for "Clean Up" exactly? (can user notify the need for clean up?)

3. what is difference between "write to FlexRAM" & "write to erased location of FlexRAM"? is that means for first time write in that location?

4. when application works for some times, assume one variable changes in every 10 minutes, after some days, we turn of the system and turn on that again, the last data of variables, will be backed up from FlexNVM to FlexRAM. can we say this time will be extended in next on/off procedure?

5. about margin term, what is difference between user & factory margin? is there any mention for their voltage values? can we change their values?

Thanks.

[danielmartynek · Accepted solution]

Hi,

1.

The elapse time is the same in both cases.

It is the Set FlexRAM Function execution time with control code 0x00.

DS rev.13, Table 35. Flash command timing specifications for S32K14x series

2.

There is no such document.

But you can use the SetFlexRAM function with control code 0x77 to get the Sector erase count.

The counter increments every time all the sectors erased are.

Regards,

Daniel

[danielmartynek]

Hello Jeorge,

Please refer to AN11983 Using the S32K1xx EEPROM Functionality
https://www.nxp.com/docs/en/application-note/AN11983.pdf

1.

Yes

2.

It is explained in AN11983,

Chapter 6 S32K1xx new quick write mode

3.2.1.4 FlexRAM used for querying write status on EEPROM
3.2.1.5 FlexRAM used to complete interrupted EEPROM quick write process

3.

Yes

4.

I’m not sure if I understand, can you elaborate?

5.

The levels are not specified and cannot be changed.

Best regards,

Daniel

[JeorgeB]

Thanks Daniel for reply,

A. assume we want to save 100 bytes (includes 25 variables) into FlexRAM. we saved all variables One time, so in FlexNVM (back up D-Flash) , we have only 100 variable. now system is reset and in start up, EEE find the last values and reload them into FlexRAM. 

B. assume we have an application which has 100 bytes (include 25 variables) in FlexRAM. we update the all variables multiple times (e.g. 200), so in D-Flash refresh (swap sectors) occurs several times. next time we reset the system, EEE find last value and reload them from FlexNVM to FlexRAM. 

my question has two parts:

1. how much is elapsed time for  loading data in A & B? is there any formula or equation to measure these times theoretically ?

2. is there any document for describing the swap algorithm in D-Flash which performed by EEE?

Thanks.