Are you aware of a development board that is running the faster speed CPU's?
We need the faster speed for our application.
-----Original Message-----
From: Richard Hendricks [mailto:richard.hendricks@motorola.com]
Sent: Friday, June 09, 2000 9:44 AM
To: 'linuxppc-embedded@lists.linuxppc.org'
Subject: Re: Running the 823 FADS board @ 72 MHZ
The FADS board are not designed to run at that speed. Just for kicks,
I've tried seeing how fast I can go without problems. At about 60 MHz
the SDRAM no longer works, and 68 MHz the DRAM starts not working. This
is with the default 50 MHz tables. With better tuning, it may be
possible
to go higher, but I doubt you could reach 72 MHz with the FADS.
Kirk Haderlie wrote:
We are trying to run the FADS board @ 72MHz and enjoying the infamous UPM
tables. Has anyone successfully run the FADS board at this speed and if
so
would you be willing to share your UPM tables. We are trying to set them
up for the SDRAM and 60-ns EDO DRAM.
Kirk Haderlie
kirk@vividimage.com
Vivid Image Engineering
--
MPC823 Applications Engineering Development
Get help from other MPC823 customers on the
comp.sys.powerpc.tech newsgroup!
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From: Richard Hendricks <hidden> Date: 2000-06-09 18:56:08
I do not know of any *development* board that is running the faster
speed CPU's in 1:1 mode. I *do* know several customers are running
their designs at 66 MHz 1:1. There is also at least 1 customer I
know of running 75 Mhz 1:1 without problems. I wrote an application
note describing how to do a high-speed SDRAM interface to the MPC823.
Hint: PC66 will NOT work at 66 MHz. PC100 in most cases won't even
work at 75 MHz. If you are interested in the app note, I recently
published it on comp.sys.powerpc.tech
Kirk Haderlie wrote:
Are you aware of a development board that is running the faster speed CPU's?
We need the faster speed for our application.
-----Original Message-----
From: Richard Hendricks [mailto:richard.hendricks@motorola.com]
Sent: Friday, June 09, 2000 9:44 AM
To: 'linuxppc-embedded@lists.linuxppc.org'
Subject: Re: Running the 823 FADS board @ 72 MHZ
The FADS board are not designed to run at that speed. Just for kicks,
I've tried seeing how fast I can go without problems. At about 60 MHz
the SDRAM no longer works, and 68 MHz the DRAM starts not working. This
is with the default 50 MHz tables. With better tuning, it may be
possible
to go higher, but I doubt you could reach 72 MHz with the FADS.
Kirk Haderlie wrote:
quoted
We are trying to run the FADS board @ 72MHz and enjoying the infamous UPM
tables. Has anyone successfully run the FADS board at this speed and if
so
quoted
would you be willing to share your UPM tables. We are trying to set them
up for the SDRAM and 60-ns EDO DRAM.
Kirk Haderlie
kirk@vividimage.com
Vivid Image Engineering
--
MPC823 Applications Engineering Development
Get help from other MPC823 customers on the
comp.sys.powerpc.tech newsgroup!
--
MPC823 Applications Engineering Development
Get help from other MPC823 customers on the
comp.sys.powerpc.tech newsgroup!
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
From: Steve Rossi <hidden> Date: 2000-06-09 19:08:42
I've got a custom 823 board running on the bench at 80MHz 1:1 with PC100 SDRAM
with no problems but I had to re-program the UPM to do it. 50MHz is a sweet spot
(at least with my memories), but above 50MHz without re-programming the UPM
you're probably violating SDRAM timing somewhere.
Steve
Richard Hendricks wrote:
I do not know of any *development* board that is running the faster
speed CPU's in 1:1 mode. I *do* know several customers are running
their designs at 66 MHz 1:1. There is also at least 1 customer I
know of running 75 Mhz 1:1 without problems. I wrote an application
note describing how to do a high-speed SDRAM interface to the MPC823.
Hint: PC66 will NOT work at 66 MHz. PC100 in most cases won't even
work at 75 MHz. If you are interested in the app note, I recently
published it on comp.sys.powerpc.tech
Kirk Haderlie wrote:
quoted
Are you aware of a development board that is running the faster speed CPU's?
We need the faster speed for our application.
-----Original Message-----
From: Richard Hendricks [mailto:richard.hendricks@motorola.com]
Sent: Friday, June 09, 2000 9:44 AM
To: 'linuxppc-embedded@lists.linuxppc.org'
Subject: Re: Running the 823 FADS board @ 72 MHZ
The FADS board are not designed to run at that speed. Just for kicks,
I've tried seeing how fast I can go without problems. At about 60 MHz
the SDRAM no longer works, and 68 MHz the DRAM starts not working. This
is with the default 50 MHz tables. With better tuning, it may be
possible
to go higher, but I doubt you could reach 72 MHz with the FADS.
Kirk Haderlie wrote:
quoted
We are trying to run the FADS board @ 72MHz and enjoying the infamous UPM
tables. Has anyone successfully run the FADS board at this speed and if
so
quoted
would you be willing to share your UPM tables. We are trying to set them
up for the SDRAM and 60-ns EDO DRAM.
Kirk Haderlie
kirk@vividimage.com
Vivid Image Engineering
--
MPC823 Applications Engineering Development
Get help from other MPC823 customers on the
comp.sys.powerpc.tech newsgroup!
--
MPC823 Applications Engineering Development
Get help from other MPC823 customers on the
comp.sys.powerpc.tech newsgroup!
--
-------------------------------------------------------
Steven K. Rossi srossi@ccrl.mot.com
Staff Engineer
Multimedia Communications Research Laboratory
Motorola Labs
-------------------------------------------------------
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
From: Richard Hendricks <hidden> Date: 2000-06-09 19:41:43
Most PC100 memory has a Cl latency of 8ns. The MPC8xx family has a
setup-time of 6ns. This gives a maximum frequency of 1/(8+6ns) = 71MHz.
I have recently seen "PC100" memory with a Cl latency of 6ns, which
gives
you 83 MHz. After talking with the design team, they say the setup
time is probably closer to 5.4ns in real-life, which gives 74MHz and
87MHz (theoretically, only looking at setup-time). This assumes, of
course, no trace delays or excessive bus capacitance. I wouldn't
productize a design that used its memory outside of spec. It is fun
to play with though.
Steve Rossi wrote:
I've got a custom 823 board running on the bench at 80MHz 1:1 with PC100 SDRAM
with no problems but I had to re-program the UPM to do it. 50MHz is a sweet spot
(at least with my memories), but above 50MHz without re-programming the UPM
you're probably violating SDRAM timing somewhere.
Steve
Richard Hendricks wrote:
quoted
I do not know of any *development* board that is running the faster
speed CPU's in 1:1 mode. I *do* know several customers are running
their designs at 66 MHz 1:1. There is also at least 1 customer I
know of running 75 Mhz 1:1 without problems. I wrote an application
note describing how to do a high-speed SDRAM interface to the MPC823.
Hint: PC66 will NOT work at 66 MHz. PC100 in most cases won't even
work at 75 MHz. If you are interested in the app note, I recently
published it on comp.sys.powerpc.tech
Kirk Haderlie wrote:
quoted
Are you aware of a development board that is running the faster speed CPU's?
We need the faster speed for our application.
-----Original Message-----
From: Richard Hendricks [mailto:richard.hendricks@motorola.com]
Sent: Friday, June 09, 2000 9:44 AM
To: 'linuxppc-embedded@lists.linuxppc.org'
Subject: Re: Running the 823 FADS board @ 72 MHZ
The FADS board are not designed to run at that speed. Just for kicks,
I've tried seeing how fast I can go without problems. At about 60 MHz
the SDRAM no longer works, and 68 MHz the DRAM starts not working. This
is with the default 50 MHz tables. With better tuning, it may be
possible
to go higher, but I doubt you could reach 72 MHz with the FADS.
Kirk Haderlie wrote:
quoted
We are trying to run the FADS board @ 72MHz and enjoying the infamous UPM
tables. Has anyone successfully run the FADS board at this speed and if
so
quoted
would you be willing to share your UPM tables. We are trying to set them
up for the SDRAM and 60-ns EDO DRAM.
Kirk Haderlie
kirk@vividimage.com
Vivid Image Engineering
--
MPC823 Applications Engineering Development
Get help from other MPC823 customers on the
comp.sys.powerpc.tech newsgroup!
--
MPC823 Applications Engineering Development
Get help from other MPC823 customers on the
comp.sys.powerpc.tech newsgroup!
--
-------------------------------------------------------
Steven K. Rossi srossi@ccrl.mot.com
Staff Engineer
Multimedia Communications Research Laboratory
Motorola Labs
-------------------------------------------------------
--
MPC823 Applications Engineering Development
Get help from other MPC823 customers on the
comp.sys.powerpc.tech newsgroup!
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/