Flash , Bottom or TOP?

[Boki]

Hi All,
Our firmware boot code is at high address ( I say 0 is low
address here), our boot code is in the last of file, I want to protect the
boot code in flash.

Should I choose bottom or top type of flash rom?

Best regards,
Boki.

 

[Tim Wescott]

Boki wrote:

Hi All,
Our firmware boot code is at high address ( I say 0 is low
address here), our boot code is in the last of file, I want to protect the
boot code in flash.

Should I choose bottom or top type of flash rom?

Assemble the following three tools:

1. The datasheets for the two flavors of flash.
2. The latest MAP file with the current boot code size, and perhaps
an estimate of what it'll be when it grows up.
3. Your brain.

Now, using these three tools in concert, decide what chip gives you the
best fit for your boot code.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

 

[Boki]

Hi, Tim,
I think we have to use bottom.

Best regards,
Boki.

"Tim Wescott" <tim@seemywebsite.com>
???????:11dvbst2p2s514@corp.supernews.com...

Boki wrote:
Hi All,
Our firmware boot code is at high address ( I say 0 is low
address here), our boot code is in the last of file, I want to protect
the boot code in flash.

Should I choose bottom or top type of flash rom?

Assemble the following three tools:

1. The datasheets for the two flavors of flash.
2. The latest MAP file with the current boot code size, and perhaps
an estimate of what it'll be when it grows up.
3. Your brain.

Now, using these three tools in concert, decide what chip gives you the
best fit for your boot code.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com