I have an application where a friend supported me with a standalone USRP
FPGA image. I used the PC only to load this image to the USRP using
gnuradio
blocks/tools. After that I can plug-off (disconnect) the USB cable from
the
PC and USRP continue to operate standalone.
My question is, has anyone tried to load USRP FPGA image without a PC?
For
example using a micro-controller (Like Microchip PIC 18F4550 which has
USB
2.0 port) with SD memory holding the image?
I don’t yet know a lot about the USRP, but I do know about USB.
The short answer is that the PIC 18F4550 processor will not help.
USB needs a “host” (typically a PC) that times & controls each data
packet and a “device” to talk to. Optionally a hub is both a device
and relay of timing & data to further devices. Both the PIC processor
and the USRP are devices, and cannot talk to each other.
Also the USRP documentation says it needs “USB2”, which I think means
it needs the “High Speed” data transfer of USB2. Whereas the PIC
18F4550 only supports the lower transfer speeds of USB1.1, and is USB2
compatible in the sense that it works with USB2 Hosts.
Some of the 16-bit and 32-bit PIC processors have a USB Host port, or
at least can operate a USB “On-The-Go” (OTG) port in host mode - but
I’m not sure if they support “High Speed” (HS) mode, and you will need
a lot of software to control the USB.
An easier path would be to look small processor boards such as those
that support embedded Linux. For instance the web page for the
Gumstix Overo Earth says it has a “USB HS Host” and a micro SD slot.
(Not micro SDHC - so you are limited to, I think, 4Gb cards.)
See: http://gumstix.com/store/catalog/product_info.php?cPath=31&products_id=211
Altera and Xilinx FPGAs can boot from a variety of small, cheap Flash
devices. I
haven’t looked at the USRP1 schematic in a while, but my guess is that
it would take
only a few mods to deadbug an appropriate Flash device and jumper as
needed. Looking
at the board, I don’t see that Matt has left a place for the typical
header with the
required signals, but there are only a few and they should be available
on the
CY7C680 pins.
Programming the Flash device is another question: one way is a socket
on the USRP1
and a cheap Flash programmer (connect to PC serial port or parallel
port).
On Thu, 2009-04-23 at 23:43 -0700, Firas A. wrote:
example using a micro-controller (Like Microchip PIC 18F4550 which has USB
2.0 port) with SD memory holding the image?
What it takes/need to do so?
What should be possible is to load the FPGA image and/or the FX2 image
using JTAG.
I think I remember that the JTAG lines are accessible on the USRP1.
It might also be possible to use a dedicated serial FPGA eeprom and
connect it directly to the FPGA. This would require hardware
modification of the USRP board.
Just look at the cyclone datasheet and application notes on the altera
site.
I don’t know if all the required pins for setting the FPGA load
operation are physically reachable on the USRP1 board.
If you don’t want to solder on your board, your only option is using a
USB2 host in some kind of form.
On Thu, Apr 23, 2009 at 11:43:19PM -0700, Firas A. wrote:
My question is, has anyone tried to load USRP FPGA image without a PC? For
example using a micro-controller (Like Microchip PIC 18F4550 which has USB
2.0 port) with SD memory holding the image?
This might work. The control end point works in both USB 2.0 and USB
1.1 mode. As long as you were only using that, you could probably get
the FX2 image and the FPGA image loaded.
It’s worth a try.
Atmel has a similar part (AT90USB1287) and has a devkit, AT90USBKEY,
that might save you some work. It’s a USB OTG 2.0 device, $30, has the
right dongle, and has a pair of 64Mbit flash chips on board. The power
supply is spec’d to 8-15V, but might be coaxed to run off something
lower. Digikey/Mouser/Arrow stocks 'em.
On Thu, Apr 23, 2009 at 11:43:19PM -0700, Firas A. wrote:
My question is, has anyone tried to load USRP FPGA image without a PC? For
example using a micro-controller (Like Microchip PIC 18F4550 which has USB
2.0 port) with SD memory holding the image?
What it takes/need to do so?
Best Regards,
Firas
Firas,
This might work. The control end point works in both USB 2.0 and USB
1.1 mode. As long as you were only using that, you could probably get
the FX2 image and the FPGA image loaded.
Atmel has a similar part (AT90USB1287) and has a devkit, AT90USBKEY,
that might save you some work. It’s a USB OTG 2.0 device, $30, has the
right dongle, and has a pair of 64Mbit flash chips on board. The power
supply is spec’d to 8-15V, but might be coaxed to run off something
lower. Digikey/Mouser/Arrow stocks 'em.
You might find a lower cost solution, but by the time you get it
working, you may have been better off using the over. I have downloaded
firmware from the Overo to the USRP via USB. The bonus is you can run
gnuradio on the Overo if needed.
Philip
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