2 Mbytes of memory

[Guest]

Hi,

My application has a PIC a I have to store about 2 mega bytes of nonvolatile data. I was looking at Ramtron, Microchip and I couldn't found nothing.

Could you help me?

Thank you.
Renoi Lumba.

[ckielstra]

Using serial chips like those from Ramtron and Microchip the largest models have a capacity of about 1Megabit I think. You could use 16 of those chips...

For larger capacities up to several Gbytes it is often better to use one of the memory cards like CompactFlash or MMC and SD cards.
CompactFlash is easy to write software for but requires something like a minimum of 14 I/O lines. MMC and SD cards use a serial interface with less I/O lines but are a little bit more difficult to write software for.
I use MMC in SPI interface mode which requires only 4 I/O lines and am very happy with this. MMC is a better choice over SD because it is easier to program and the specifications are better available. Programming examples can be found by using the search function of this forum.

One note on MMC/SD: The minimum block size for writing data is 512 bytes, make sure to choose a PIC processor with at least this amount of spare RAM available (reading data is no problem as this can be done in sizes of 1 bytes up).

[arunb]

Hi,

Could you post the part numbers for them ( assuming they are in IC form) ??

Are these the ones they use in cameras or mobile phones ??

thanks
arun

[ckielstra]

Yes, they are the ones used in photocameras and mobile phones.