52832 flash erase time

[William.wei]

hi support team，

according to our 832 spec, flash erase time minimal is 2.05ms, max is 89.7ms,

 i have tested that when no soft device this time is 2.05ms, so this time is impact by soft device indeed.

may i ask any other factors that impact the flash erase time. below is what i can list:

1. 52832 hardware version?

2. soft device version. for example 7.0.1 and 7.2.0?

3. temperature.

4. S112 and S132?

5. BLE connection interval for 7,5ms and 30ms difference.（i guess this is important）

[tesc]

Hi,

The minimum and maximum flash erase times are for the (hardware) flash erase itself, and not for waiting time due to scheduling by e.g. the SoftDevice. The values are for the full temperature range, for the full operational voltage range, for the full lifetime of the device, and your exact timing will be affected by those parameters. This can be hard to predict, especially the impact of flash wear. You should design your solution so that it can handle the worst case numbers.

Please note that delays due to scheduling comes on top of the electrical specification. The SoftDevice will schedule erases only when the full maximum time is available for scheduling.

Regards,
Terje

[William.wei]

hi tesc,

i saw some tickets about this:

 Don't understand page numbering for sd_flash_write and sd_flash_erase 

am i wrong?

Regards,

William.

[tesc]

Hi,

I am sorry, but I do not quite see the connection between this case and the one you refer to, and/or what you may be wrong about.

The callback functionality from the SoftDevice will add some delay, yes, in addition to the delay from the hardware specification. This is because any flash operation must be scheduled by the SoftDevice, which means the SoftDevice must find a suitable time for scheduling it. After some time, the SoftDevice will return with a callback (an event) signalling whether the operation succeeded or not.

Please note that the "pstorage" library / module, which is mentioned in the other case, has been replaced by fstorage. (The case is from 2014, which is 9 years ago, and fstorage replaced pstorage around that time.) Typically you want to use fstorage for direct access to flash, and you want to use the flash data storage (FDS) library if you want to store pieces of data to flash if timing and the location of the data is not important.

Please also note that Wednesday and Thursday this week are public holidays in Norway. I will also be out-of-office on Friday. This means you should not expect more answers from me before Monday. If it is urgent, please create a new ticket, which someone else may tend to on Friday if there is enough time. We are low on staff that day, so  there is no guarantee. I am sorry for any inconvenience.

Regards,
Terje