Hi Gerald
Has the BeagleboardXM been designed to accept a NAND / RAM POP chip in
the future?
Just wondering if there are any hardware changes required or just u-
boot / Kernel changes?
BTW, why was the NAND removed on the XM version was it because of
availability or other reasons?
Thanks
Regards,
John
Yes. In fact, it contained one in the past. The first boards had NAND on them. In order to boot from NAND you would need to change the boot pin resistor loading. NAND was removed because people were trashing the NAND and could not figure out how to re-flash the NAND. We were getting hit hard on the RMA side with us having to reflash it for them. It also allowed for easier switching back to a known good state by going back to the SD card that came with the system.
Gerald
Thanks for the reply Gerald, we are designing a thin client based on
the Beagleboard and would like to add a NAND option as well as SD...
I want to eventually be able to network boot the board, as step one we
are modifying u-boot to add USB Device networking, tftp etc
Step two is to add support to u-boot for the USB Ethernet chip
John
On the -xM we use 512MB of DDR which contains 4 die in the memory package. Adding another die for NAND would make that a stack of 5 die. I am not sure if the POP suppliers have that configuration available or not, hence the decision to drop the NAND was sealed at that point. Numonyx had such a configuration, but that is no longer supported. You can however easily add NAND on board as the GPMC bus that connects to the NAND is available on the processor.
Gerald
Thanks Gerald,
We will look at adding NAND on board, the other thing I am considering
is a second Ethernet port using this
www.smsc.com/media/Downloads_Public/Data_Sheets/9221.pdf
Any comments or other suggestions?
This should be OK, but I have not dug into deeply. I suggest you look at the DM350 EVM from TI (Mistral). It has a LAN devcie on it that hooks to the GPMC bus. If that one will work for you, the Linux drivers are already ported and ready to go.
Gerald
Great!
Thanks Gerald
John
Hi Gerald,
We had a look at the DM350 EVM and it has a LAN9220, the LAN9221 looks
to be a newer version of this chip, we are investigating whether the
LAN9221 would be a better choice
Also Page 90 of the BeagleBoard-xM System Ref. Manual indicates that
there is a legacy option on the board for the old C4 version, we are
planning to remove this option, can you think of any reason to keep
this option anymore?
Thanks
John
I guess it all depends on what your overall needs are based on what your end goal is. I can’t really answer that without know what you are trying to do. There could be a situation to where you may need it.
Gerald
Hi Gerald,
We are using the board as a thin client, we will be using the DSP to
run a Video decoder...
I have a question on DVI, I noticed you advise users not to plug in a
monitor with the board powered up, is there some protection that was
left off the board to save cost, seems strange that this would be an
issue?
John
It is not a protection issue. When the part gets damaged the signal degrades by a few millivolts. This is enough for some monitors not to work. The TFP410 would still work on other monitors. The failure mode in the TFP410 was never fully understoodd. The theory is that it gets damages by sending current into the monitor when the cable is plugged in with the board powered.
Removing the legacy mode is definitley your call. I see know issue doing it.
Gerald.
Gerald, have you ever seen the TFP410 part damaged on the XM version?
I see you added U5B did that help?
We are doing this to save space and simplify the routing, do you know
if anybody using a XM board has changed to legacy mode and why?
Thanks
John
Out of the 29,000 boards we have shipped we have seen the issue maybe 25 times. U5B was in the original design as well. Nobody has changed to legacy mode that I know of. If they did they would loose the 720P capability. There isn’t really a reason to do it if nothing else from a SW compatibility standpoint.
Gerald
Thanks Gerald
John