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Re: What is the different between "ROM" and "ROMRAM" in the Bootup type ??
Dear Andrew,
I see, I will try it.
Thank you for your help very much.
Steven Cheng
----- Original Message -----
From: "Andrew Lunn" <andrew@lunn.ch>
To: "Steven_cheng" <05071@alphanetworks.com>
Cc: "Andrew Lunn" <andrew@lunn.ch>; <ecos-discuss@sources.redhat.com>
Sent: Monday, July 04, 2005 3:41 AM
Subject: Re: [ECOS] What is the different between "ROM" and "ROMRAM" in the
Bootup type ??
> On Sun, Jul 03, 2005 at 09:41:27AM +0800, Steven_cheng wrote:
> > Dear Andrew,
> >
> > Thank you for you reply, but I still confuse about the following
> > questions.
> >
> > 1) When the board powers on, does the CPU need to know which type and
> > vendor of ROM flash?? (ex. AMD 29LV040B)
>
> No. It should be able to read from any type/vendor. You only need to
> know more when you come to erase/write. But its not the CPU that does
> what, its you application program.
>
>
> > 2) How does the CPU know the memory address which the ROM locates ??
>
> It is hardwired. Read the data sheet for your processor and look at
> the schematics to see what chip select it is using.
>
> Andrew
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