The ECC needs to be stored. as ones ane zeroes

By: Heikki Kultala (, November 26, 2022 12:48 am
Room: Moderated Discussions
anon2 ( on November 25, 2022 4:07 pm wrote:
> Heikki Kultala ( on November 25, 2022 7:31 am wrote:
> > The ECC needs to be stored. as ones ane zeroes
> ECC can be stored out of band. Flash controllers can disable on chip ECC and do their own.
> Then, depending on the translation layer, ECC adjustments could be written independently,
> e.g., streamed out to the log. If you had a frequently updated page, you could keep the ECC
> in a cache even, and only write it out on power failure or when the page is filled.
> I don't know of if anybody is actually doing that (multi programming the NAND) or if it would
> be very useful or even possible. Programming a modern NAND is a fine art and there are all
> sorts of effects from every operation (read, program, erase) including on nearby devices.

Storing the ECC to totally separate place as the data is horribly inefficient.

Two reads to totally separate places is considerably more expensive than one slightly wider read.

And storing the ECC bits to somewhere else does not solve the actual problem - they still have to be erased. If storing them to different kind of flash memory that has much smaller erase blocks - then that memory is MUCH more expensive per bit than the memory used to store the actual data.

Making everything much bigger, more expensive, slower and more power-hungry.

That something is theoretically possible and that something makes sense are totally different things.

< Previous Post in ThreadNext Post in Thread >
TopicPosted ByDate
Is 1 more expensive than 0?Andrey2022/11/21 05:23 AM
  Is 1 more expensive than 0?Juha Lainema2022/11/21 06:15 AM
  Is 1 more expensive than 0?Adrian2022/11/21 07:21 AM
    Is 1 more expensive than 0?anon22022/11/21 05:29 PM
  switching between 0 and 1 is what consumes powerHeikki Kultala2022/11/21 07:23 AM
    Thank you all for your answers. (NT)Andrey2022/11/21 08:29 AM
  Is 1 more expensive than 0?Foyle2022/11/21 08:58 AM
    Is 1 more expensive than 0?Michael S2022/11/21 10:51 AM
    Is 1 more expensive than 0?Captain Obvious2022/11/21 11:29 AM
      obvious stuffanonymou52022/11/21 02:25 PM
        obvious stuffAndrey2022/11/21 02:50 PM
          obvious stuffMichael S2022/11/21 03:43 PM
  SRAM is bistableAnon2022/11/21 10:50 AM
    SRAM is bistableAndrew Clough2022/11/22 05:53 AM
  NAND Flash 1 and 0jokerman2022/11/24 01:13 PM
    NAND Flash 1 and 0Joern Engel2022/11/25 12:00 AM
      NAND Flash 1 and 0Ungo2022/11/25 02:26 AM
        The ECC needs to be stored. as ones ane zeroes (NT)Heikki Kultala2022/11/25 08:31 AM
          The ECC needs to be stored. as ones ane zeroesanon22022/11/25 05:07 PM
            The ECC needs to be stored. as ones ane zeroesHeikki Kultala2022/11/26 12:48 AM
              The ECC needs to be stored. as ones ane zeroesanon22022/11/26 02:00 AM
Reply to this Topic
Body: No Text
How do you spell tangerine? 🍊