sd_flash_page_erase on nrf52840 takes a long time

[Youssif]

Hi

We are seeing a significant delay in a flash-related operation on the nrf52840, specifically using the function sd_flash_page_erase() When we use that function to erase flash it takes up to 3 times longer on the nrf52840 than it does on the nrf52832 running the exact same code. Is this an expected behaviour/known issue?

We are using softdevice S140 v5.0.0-3.alpha, SDK v14.0.0 and the nr52840 preview development kit.

Thanks

[Sigurd]

Hi,

The behavior you are seeing is expected. We use a different type of flash on the nRF52840 than on the nRF52832. It takes a longer time to erase a page on the nRF52840, but it should be faster to write a page on the nRF52840 compared to the nRF52832.

[Youssif]

From the links, nRF52840's tWRITE, tERASEPAGE, and tERASEALL (41us, 85ms, 169ms) are all shorter than nrf52832's tWRITE, tERASEPAGE, and tERASEALL (338us, 89.7ms, 295.3ms)?