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Subject: [ rockbox-Feature Requests-566169 ] Bigger DRAM Mod
From: noreply_at_sourceforge.net
Date: 2002-06-08


Feature Requests item #566169, was opened at 2002-06-08 06:34
You can respond by visiting:
http://sourceforge.net/tracker/?func=detail&atid=439121&aid=566169&group_id=44306

Category: Hardware Modifications
Group: None
Status: Open
Priority: 5
Submitted By: Nobody/Anonymous (nobody)
Assigned to: Nobody/Anonymous (nobody)
Summary: Bigger DRAM Mod

Initial Comment:
This is a follow up to the More RAM discussion.
Unfortunately I keep on getting an error preventing me
from posting that as a follow up.

The chip already does most of the work except it can
shift address bit by more than 10-bits on its own. An
external 2:1 mux is all that's needed to let you use
4Mx16 DRAM chips.

Guys all you need to do is help it shift 11-bit
addresses by mux the address bits !!

DRAM A[0] = SH1 A[11] when /RAS ='1' SH1 A[0]
otherwise.

You might have to adjust for CAS before RAS refresh
timer though...

No need for double banks of DRAM nor SRAM here...
Just need to understand datasheets.

Ref: See Page 143 on SH1 hardware manual

----------------------------------------------------------------------

You can respond by visiting:
http://sourceforge.net/tracker/?func=detail&atid=439121&aid=566169&group_id=44306



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