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Address Mapping LPC24XX

Started by Mad I.D. January 4, 2009
I just connected a 32MB of x32 SDRAM (one IC) on LPC2478 chip and
unfortunately have some doubts.

SDRAM Spec:
4k Row (12bits) x 512 column (9bits) x 32 bits.

I was having trouble to figure out where to connect bank address pins
and found in some other document (not user manual) that
A14:A11->BA1:BA0 should be OK. Why is this not documented in user
manual? Did I miss something ? [A12 is not used at all, row addressing
is A0-A11].

The reason I'm writing this is because I don't understand Address
Mapping table on page 84 of the user manual.

I can't find appropriate Address Mapping (AM) bits setting for my
SDRAM.

There is no ->
"4 bank, row length=12, column length=9 (2Mx32) 32MB"

Can someone please clear this up for me a little bit? Thank you very
much.


On Jan 4, 12:16=A0pm, Mad I.D. <madi...@MOOOOVEyahoo.com> wrote:
> I just connected a 32MB of x32 SDRAM (one IC) on LPC2478 chip and > unfortunately have some doubts. > > SDRAM Spec: > 4k Row (12bits) x 512 column (9bits) x 32 bits. > > I was having trouble to figure out where to connect bank address pins > and found in some other document (not user manual) that > A14:A11->BA1:BA0 should be OK. Why is this not documented in user > manual? Did I miss something ? [A12 is not used at all, row addressing > is A0-A11]. > > The reason I'm writing this is because I don't understand Address > Mapping table on page 84 of the user manual. > > I can't find appropriate Address Mapping (AM) bits setting for my > SDRAM. > > There is no -> > "4 bank, row length=3D12, column length=3D9 (2Mx32) 32MB" > > Can someone please clear this up for me a little bit? Thank you very > much.
Which SDRAM chip is this?