Am29LV065D woes -- ZFMicro MachZ help?

Changwoo Ryu cwryu at
Mon Aug 13 23:10:38 EDT 2001

Luke <luke_epsilon at> writes:

> I appreciate the help so far - I have been trying to read what I can about
> my system.
> --- Vipin Malik <vipin at> wrote:
> > 
> > That's entirely dependent on your hardware- as to which address range it
> > decodes the chip select (CS) line going to the flash chip.
> ...
> > If it is going to your (embedded PC on a chip) processor (if that's the 
> > case- like in an AMD SC520 or Intel 386EX) then either look in the bios 
> > settings where the PAR (programmable address range) chip select
> > registers are being set or you may have to program them yourself- say in
> > the physmap.c file before you do the probe for the flash chip.
> The flash is going directly to the processor.  In this case it is a
> ZFMicro MachZ chip (Cyrix 486 dx4) - the documentation on the physical
> address space is very confusing to me.  Has anyone tried using MTD for
> this chip?
> In the bios, one can configure mem_cs_0 (0-3 actually) memory page size,
> memory base, and memory offset.  I have 2 Am29LV065D 8M flash chips - one
> linked to mem_cs_0 and the other to mem_cs_1.  The confusing part comes
> with the Rom Extension Linux Loader that comes with the platform.  Looking
> at the assemby for this loader it seems as though it uses the default
> settings set in bios for mem_cs_0 and then the loader changes these values
> to address an initrd, and kernel address space.  

You don't need the register values (set by the linux loader) after
linux/initrd loading.  Then the regsiter values should be changed
before probing the flash.

You can read the H/W manual "ZF-Logic" section about setting the

Changwoo Ryu

More information about the linux-mtd mailing list