Lifetime of SDCard if only read with intensity high and continuous!

[lemta2000]

Hello,
I intend to use sdcard as ROM . As far as I know that flash has ~100.000 program/erase cycles. But I don't know about read cycle. In my project, I have used a Microcontroller to interface with sdcard, however only read(not write) data from sdcard then load to internal RAM of Microcontroller and further processing. This operation is repeated in a infinite loop (thus I have compare it as act of RAM which works with intensity high and continuous). And my question is it has any limit of read cycle as with write operation and life time of sdcard when compare with sdram in the case of use as above description?

Thanks!

 

[CMOS]

Look at the "Data Retention" specification of the SD card. Under normal circumstances and normal use the data retention time for a memory card is at least 10 years. Some memory card manufactures claim up to 100 years of usage life.

 

[doraemon]

Hello!

Anyway an SD card instead of ROM is a bad solution. Usually you use a ROM for data that you
ABSOLUTELY want to stay forever on your hardware, and absolutely want to have access at any
time. What if the SD card connector gets loose for some reason?
Why not using a flash chip?

Dora.

 

[jeffrey samuel]

SD card can suit more like a backup rather than a ROM in reality better go for it if you have no other alternative

ROM's need to run at all time there is to be no implications and this has a capacity of creating fatal errors so if you are confident that the SD will never be disturbed then go forward

 

[tomeko]

First: common MLC memories have ~10k erase/write cycles guaranteed, for TLC it could be as low as 500 cycles. Heavy erase/write affects also data retention.
As for read cycles - I have done some test on SLC FLASH memories (1Gbit, 2 kB page and some with 512 B page) and they were able to withstand ~2000000 read cycles until first bit from page was loss (which was correctable by ECC). MLC memories have ~100000 cycles read endurance. When first bit is lost memory controller should refresh whole page (or even block) but I have no idea if this is common feature for controllers used in SD card.
It's hard to find SD card with detailed specification - it's impossible for consumer grade cards (and from my experience card specification changes without notification). Use industrial cards - at least their behavior is more consistent.

 

[FvM]

The problem of limited read endurance is discussed under Temporary Failures and Read Disturb in this Micron application note:

**broken link removed**