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Discussion Groups | AT91SAM ARM | Implementing Mass Storage Device in AT91
For users of the Atmel AT91SAM7 and AT91SAM9 ARM CPU chips. Atmel has taken a new direction by combining on chip flash and ram with the ARM CPU on a single die. This provides low cost devices for small systems using the ARM CPU. This group is to exchange information to help users get started and learn how to use the devices.
Implementing Mass Storage Device in AT91 - ivan...@gmail.com - Jan 31 9:38:49 2008
Hello,
I am implementing mass storage device. It should work with windows OS. I need to use only simple commands to write to flash memory (little data) and read from it (much data). I will be using BULK read and write. I wanted to ask if I should make simple SCSI and MSD functions from scratch or use some ready made functions instead. Please recommend me, and give me some links for ready functions or documentation about MSD.
Best regards, Ilan.
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
I am implementing mass storage device. It should work with windows OS. I need to use only simple commands to write to flash memory (little data) and read from it (much data). I will be using BULK read and write. I wanted to ask if I should make simple SCSI and MSD functions from scratch or use some ready made functions instead. Please recommend me, and give me some links for ready functions or documentation about MSD.
Best regards, Ilan.
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
RE: Implementing Mass Storage Device in AT91 - microbit - Jan 31 10:22:39 2008
Hi,
For MSD you only need RBC. There is an app of Atmel demonstrating this.
It is/was code you need to request after NDA, but I think I saw it public on atmel.com a while
ago. It has 2 PDFs with it explaining flow of things.
Best Regards,
Kris
-----Original Message-----
From: A...@yahoogroups.com [mailto:A...@yahoogroups.com] On Behalf Of i...@gmail.com
Sent: Friday, 1 February 2008 1:20 AM
To: A...@yahoogroups.com
Subject: [AT91SAM] Implementing Mass Storage Device in AT91
Hello,
I am implementing mass storage device. It should work with windows OS. I need to use only simple
commands to write to flash memory (little data) and read from it (much data). I will be using BULK
read and write. I wanted to ask if I should make simple SCSI and MSD functions from scratch or use
some ready made functions instead. Please recommend me, and give me some links for ready functions
or documentation about MSD.
Best regards, Ilan.
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
For MSD you only need RBC. There is an app of Atmel demonstrating this.
It is/was code you need to request after NDA, but I think I saw it public on atmel.com a while
ago. It has 2 PDFs with it explaining flow of things.
Best Regards,
Kris
-----Original Message-----
From: A...@yahoogroups.com [mailto:A...@yahoogroups.com] On Behalf Of i...@gmail.com
Sent: Friday, 1 February 2008 1:20 AM
To: A...@yahoogroups.com
Subject: [AT91SAM] Implementing Mass Storage Device in AT91
Hello,
I am implementing mass storage device. It should work with windows OS. I need to use only simple
commands to write to flash memory (little data) and read from it (much data). I will be using BULK
read and write. I wanted to ask if I should make simple SCSI and MSD functions from scratch or use
some ready made functions instead. Please recommend me, and give me some links for ready functions
or documentation about MSD.
Best regards, Ilan.
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
Re: Implementing Mass Storage Device in AT91 - ivan...@gmail.com - Feb 7 6:44:19 2008
I think that using only RBC for mass storage won't suffice. I need to maintain a FAT file
system. For this I will need to use SCSI protocol.
Tell me if I am not right.
Ilan.
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
Tell me if I am not right.
Ilan.
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
Re: Re: Implementing Mass Storage Device in AT91 - Andre Gompel - Feb 7 12:04:20 2008
Ilan:
SCISI (or derivative), is pretty much the lowest
layer, and deal with LBA's (logical block adress on a
storage device) or in old parlance sector number and
size of transfer.
The files system, FAT or other, deal with nodes
numbers, file names etc...
Normally the SCSI level should suffice, because the OS
device drivers will call LBA's for R/W.
But this is only true if you have an existing OS!
The LBA level is almost the physical level, and should
not be too hard to implement, most of the work being
in the exception processing. (bad sectors etc...)
Good luck.
Andre
ps are you in Israel?
--- i...@gmail.com wrote:
> I think that using only RBC for mass storage won't
> suffice. I need to maintain a FAT file system. For
> this I will need to use SCSI protocol.
> Tell me if I am not right.
>
> Ilan.
Andre Gompel
a...@yahoo.com
____________________________________________________________________________________
Be a better friend, newshound, and
know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
SCISI (or derivative), is pretty much the lowest
layer, and deal with LBA's (logical block adress on a
storage device) or in old parlance sector number and
size of transfer.
The files system, FAT or other, deal with nodes
numbers, file names etc...
Normally the SCSI level should suffice, because the OS
device drivers will call LBA's for R/W.
But this is only true if you have an existing OS!
The LBA level is almost the physical level, and should
not be too hard to implement, most of the work being
in the exception processing. (bad sectors etc...)
Good luck.
Andre
ps are you in Israel?
--- i...@gmail.com wrote:
> I think that using only RBC for mass storage won't
> suffice. I need to maintain a FAT file system. For
> this I will need to use SCSI protocol.
> Tell me if I am not right.
>
> Ilan.
Andre Gompel
a...@yahoo.com
____________________________________________________________________________________
Be a better friend, newshound, and
know-it-all with Yahoo! Mobile. Try it now. http://mobile.yahoo.com/;_ylt=Ahu06i62sR8HDtDypao8Wcj9tAcJ
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
Re: Implementing Mass Storage Device in AT91 - ivan...@gmail.com - Feb 14 9:10:23 2008
As I understood LBA is lower level than SCSI, so SCSI uses it.
RBC (reduced block commands) - I am not sure that this will suffice reading and writing/deleting of files.
Please explain me in more depth.
ps - Yes I am in Israel.
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
RBC (reduced block commands) - I am not sure that this will suffice reading and writing/deleting of files.
Please explain me in more depth.
ps - Yes I am in Israel.
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
Re: Re: Implementing Mass Storage Device in AT91 - Foltos - Feb 14 9:45:34 2008
Hi,
I assume you are implementing a mass-storage device (one that can be
connected to a PC).
This device needs to implement two layers. Some command set interpreter
(SCSI, RBC) and a medium access layer (MMC driver, etc...). The command
set interpreter is just a standard interface to the medium access layer.
The USB host will access the medium using this ifc.
On the host side you need the following layers: file system -> SCSI or
RBC ->USB.
The best is to go for SCSI because most modern operating system supports
this layer already.
If you need to access the media from the embedded side too, the you need
a file system. This can use the SCSI interpreter or directly the medium
access layer. Concurrent access by the embedded side and USB host is not
possible. This is because none of the file system drivers can know what
structures have been changed by the other.
Foltos
i...@gmail.com wrote:
>
> I think that using only RBC for mass storage won't suffice. I need to
> maintain a FAT file system. For this I will need to use SCSI protocol.
> Tell me if I am not right.
>
> Ilan.
>
>
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
I assume you are implementing a mass-storage device (one that can be
connected to a PC).
This device needs to implement two layers. Some command set interpreter
(SCSI, RBC) and a medium access layer (MMC driver, etc...). The command
set interpreter is just a standard interface to the medium access layer.
The USB host will access the medium using this ifc.
On the host side you need the following layers: file system -> SCSI or
RBC ->USB.
The best is to go for SCSI because most modern operating system supports
this layer already.
If you need to access the media from the embedded side too, the you need
a file system. This can use the SCSI interpreter or directly the medium
access layer. Concurrent access by the embedded side and USB host is not
possible. This is because none of the file system drivers can know what
structures have been changed by the other.
Foltos
i...@gmail.com wrote:
>
> I think that using only RBC for mass storage won't suffice. I need to
> maintain a FAT file system. For this I will need to use SCSI protocol.
> Tell me if I am not right.
>
> Ilan.
>
>
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )