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Discussion Groups | AT91SAM ARM | data bus problem
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.
data bus problem - Bernd - Aug 13 13:56:08 2008
Hi,
I`m working with the AT91SAM9260 and the AT49BV160D nor flash memory.
I`m able to read out the flash manufactor code - therefore I have to
write 0x98 at any adress within the flash. But when I try to read out
the cfi code QRY - the command is 0x90 at any adress - I always get
also the manufactor code. It seems that I have a problem within the
databus.
Which problem could make this behaviour? The flash memory is correct
connected to the controller and there`s no other IC on the databus. The
trace length is approximately 80mm.
best regards
Bernd
------------------------------------
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
I`m working with the AT91SAM9260 and the AT49BV160D nor flash memory.
I`m able to read out the flash manufactor code - therefore I have to
write 0x98 at any adress within the flash. But when I try to read out
the cfi code QRY - the command is 0x90 at any adress - I always get
also the manufactor code. It seems that I have a problem within the
databus.
Which problem could make this behaviour? The flash memory is correct
connected to the controller and there`s no other IC on the databus. The
trace length is approximately 80mm.
best regards
Bernd
------------------------------------
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
Re: data bus problem - Charles Manning - Aug 13 18:19:11 2008
On Thursday 14 August 2008 05:56:02 Bernd wrote:
> Hi,
>
> I`m working with the AT91SAM9260 and the AT49BV160D nor flash memory.
>
> I`m able to read out the flash manufactor code - therefore I have to
> write 0x98 at any adress within the flash. But when I try to read out
> the cfi code QRY - the command is 0x90 at any adress - I always get
> also the manufactor code. It seems that I have a problem within the
> databus.
>
> Which problem could make this behaviour? The flash memory is correct
> connected to the controller and there`s no other IC on the databus. The
> trace length is approximately 80mm.
First off I would try to run this with as many wait states and as slow a clock
as possible to see if that makes a difference.
Some of the AT91xxx devices need to be configured to use some pins as
address/data pins. If that is not done then the address bus does not get
mapped to the pins and you will not access the external devices properly. If
you have a logic analyser that will help here.
------------------------------------
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
> Hi,
>
> I`m working with the AT91SAM9260 and the AT49BV160D nor flash memory.
>
> I`m able to read out the flash manufactor code - therefore I have to
> write 0x98 at any adress within the flash. But when I try to read out
> the cfi code QRY - the command is 0x90 at any adress - I always get
> also the manufactor code. It seems that I have a problem within the
> databus.
>
> Which problem could make this behaviour? The flash memory is correct
> connected to the controller and there`s no other IC on the databus. The
> trace length is approximately 80mm.
First off I would try to run this with as many wait states and as slow a clock
as possible to see if that makes a difference.
Some of the AT91xxx devices need to be configured to use some pins as
address/data pins. If that is not done then the address bus does not get
mapped to the pins and you will not access the external devices properly. If
you have a logic analyser that will help here.
------------------------------------
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
Re: data bus problem - bernd schuster - Aug 14 2:30:09 2008
I try to use a slower configuration, but without success. Now the master
clock is 50MHz and I use maximal wait states.
AT91C_BASE_SMC->SMC_SETUP0 = 0x00000002;
AT91C_BASE_SMC->SMC_PULSE0 = 0x000F000D;
AT91C_BASE_SMC->SMC_CYCLE0 = 0x000F000F;
AT91C_BASE_SMC->SMC_CTRL0 = 0x000F1003;
>Some of the AT91xxx devices need to be configured to use some pins as
>address/data pins.
At the AT91SAM9260 there are no other pin configuration. The example I`m
using is direct from atmel and I only changed the settings for the external
flash memory.
Maybe someone of you is working with a similar configuration and can send me
your excact register settings.
best regards
Bernd
2008/8/14 Charles Manning
> On Thursday 14 August 2008 05:56:02 Bernd wrote:
> > Hi,
> >
> > I`m working with the AT91SAM9260 and the AT49BV160D nor flash memory.
> >
> > I`m able to read out the flash manufactor code - therefore I have to
> > write 0x98 at any adress within the flash. But when I try to read out
> > the cfi code QRY - the command is 0x90 at any adress - I always get
> > also the manufactor code. It seems that I have a problem within the
> > databus.
> >
> > Which problem could make this behaviour? The flash memory is correct
> > connected to the controller and there`s no other IC on the databus. The
> > trace length is approximately 80mm.
>
> First off I would try to run this with as many wait states and as slow a
> clock
> as possible to see if that makes a difference.
>
> Some of the AT91xxx devices need to be configured to use some pins as
> address/data pins. If that is not done then the address bus does not get
> mapped to the pins and you will not access the external devices properly.
> If
> you have a logic analyser that will help here.
>
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )
clock is 50MHz and I use maximal wait states.
AT91C_BASE_SMC->SMC_SETUP0 = 0x00000002;
AT91C_BASE_SMC->SMC_PULSE0 = 0x000F000D;
AT91C_BASE_SMC->SMC_CYCLE0 = 0x000F000F;
AT91C_BASE_SMC->SMC_CTRL0 = 0x000F1003;
>Some of the AT91xxx devices need to be configured to use some pins as
>address/data pins.
At the AT91SAM9260 there are no other pin configuration. The example I`m
using is direct from atmel and I only changed the settings for the external
flash memory.
Maybe someone of you is working with a similar configuration and can send me
your excact register settings.
best regards
Bernd
2008/8/14 Charles Manning
> On Thursday 14 August 2008 05:56:02 Bernd wrote:
> > Hi,
> >
> > I`m working with the AT91SAM9260 and the AT49BV160D nor flash memory.
> >
> > I`m able to read out the flash manufactor code - therefore I have to
> > write 0x98 at any adress within the flash. But when I try to read out
> > the cfi code QRY - the command is 0x90 at any adress - I always get
> > also the manufactor code. It seems that I have a problem within the
> > databus.
> >
> > Which problem could make this behaviour? The flash memory is correct
> > connected to the controller and there`s no other IC on the databus. The
> > trace length is approximately 80mm.
>
> First off I would try to run this with as many wait states and as slow a
> clock
> as possible to see if that makes a difference.
>
> Some of the AT91xxx devices need to be configured to use some pins as
> address/data pins. If that is not done then the address bus does not get
> mapped to the pins and you will not access the external devices properly.
> If
> you have a logic analyser that will help here.
>
(You need to be a member of AT91SAM -- send a blank email to AT91SAM-subscribe@yahoogroups.com )