Electronics > Projects, Designs, and Technical Stuff
NAND flash with two chip-select
(1/1)
zphaze:
Hi,
I want to use this NAND flash chip, which has a capacity of 64Gbit. *(datasheet http://pdf.datasheet.live/e35a5359/micron.com/MT29F64G08CBABBWP-12%3AB.pdf)
On the pinout, I have two chip enable PINs (CE#/CE2#) :
This chip has two dies inside the same package, but I technically only have one NAND_CE pin on my MCU (I don't have two).
I wonder if anybody being familiar with NAND interfacing knows if it's doable to tie both chip enable (CE) PINs with a logic gate, so that if one needs to be enabled, both will always be enabled at the same time.
Is the chip somewhat using the chip enable PIN as an "extra addressing bit" so that we cannot really enable both because the addressing will become confused (i.e. if both dies have the same 00h-FFh addresse ranges or something like that), or is it doable to have one PIN driving the two chip selects with logic glue.
Thanks!
QuitButton:
Page 24 of the datasheet shows them as being separate logical units, so its in effect 2 separate chips in one case. So your "extra addressing pin" view of how it works is what it says it does.
Or in other words, you need to enable each LU individually.
thm_w:
Its a distinct die so the memory addressing is going to be the same.
Maybe some sort of address decoding or using a general IO pin is possible? What processor are you using?
--- Quote ---Asynchronous Enable/Standby
A chip enable (CE#) signal is used to enable or disable a target. When CE# is driven LOW, all of the signals for that target are enabled. With CE# LOW, the target can acceptcommands, addresses, and data I/O. There may be more than one target in a NAND Flash package. Each target is controlled by its own chip enable; the first target (Target 0)is controlled by CE#; the second target (if present) is controlled by CE2#, etc
--- End quote ---
David Hess:
--- Quote from: zphaze on July 14, 2020, 09:17:00 pm ---Is the chip somewhat using the chip enable PIN as an "extra addressing bit" so that we cannot really enable both because the addressing will become confused (i.e. if both dies have the same 00h-FFh addresse ranges or something like that), ...
--- End quote ---
That is effectively exactly what it is, an extra address bit which requires external decoding.
QuitButton:
Page 2 of the datasheet shows different Classifications are available with different die numbers. Is there one available in the size you want with a single die?
Navigation
[0] Message Index
Go to full version