[U-Boot-Users] Flash Replacement for AT91RM9200-EK

[Erdmann, Thomas]

Hello Dave,

> -----Ursprüngliche Nachricht-----
> Von: Liu Dave-r63238 [mailto:DaveLiu at freescale.com] 
> Gesendet: Freitag, 18. August 2006 09:03
> An: Erdmann, Thomas; u-boot-users at lists.sourceforge.net
> Betreff: RE: [U-Boot-Users] Flash Replacement for AT91RM9200-EK
> 
> > Hello List,
> > i use a custom Board based on the AT91RM9200-EK.
> > Now i want to Replace the Nor Flash AT49BV6416 by a larger one from 
> > Spanion.
> > The older Atmel chip specifies 70ns Access Time, the most usual 
> > Spanion chips are slower in the 100ns Range.
> 
> Are you still using static memory controller? 
I use the 16 Bit parallel Flash for the U-Boot start.
> 
> > As i read the CPU Datasheet correct at 60MHz EBI Speed the slowest 
> > Factor 1/4 gives 67ns Cycle Time.
> Is the 67ns BFC clock cycle time? I think so.
This is IMHO the slowest timing for the external parallel Flash.
> 
> > Does anyone know, how Access Time for the parallel Flash is 
> calculated 
> > and what Speed Grade is needed for a stable U-Boot out of it ?
> 
> please refer to datasheet about access time's description.
> 
> > Could a slower (100ns) Chip be used, how can this be adjusted ?
> > Are there any additional Parameters for the Flash Chip to care of 
> > (Burst Mode, Multi Bank) ?
> 
> I think the controller should support 100ns chip,  if the 
> timing is not enough, You can insert wait cycle for the access?
To change the Wait States there must a Program be already running.
The first Opcode Fetches after Reset can't be slowed down by any programmable Logic.
This Timing is adjusted by Hardware, but what are the Parameters for the AT91RM9200 ? 
> 
> -Dave
> 
> 
>