Forums

Terasic DE1 board commentary

Started by H. Peter Anvin November 30, 2008
Hello,

I am in the process of porting a project of mine from the Cyclone Nios
Development Kit to the Terasic DE1 board.  The main reason for this is
to be able to run on less expensive hardware and thus make the project
available to more people (hence "get a better board" is not really an
easy answer.)  My interest is mostly in computing projects, so my views
are certainly biased in that direction.

Unfortunately, I have run into a few issues with the DE1 board.  I
thought I'd post them here (and please let me know if there is a better
place to send this) in the hope that a future board (Cyclone III-based,
maybe?) might address these.  Please don't get me wrong - this is a
great board at a great price; I think, however, that a few things would
make it even better.

1. The SD card slot only connects a handful of signals.  In particular,
it does not connect the two switch pins on the socket (card detect and
write protect.)  This makes it much harder than it needs to be to handle
card removal and insertion.

2. Similarly, the serial port doesn't connect more than the transmit and
receive signals, even though there is a 2/2 transceiver on the board.
Having at least DTR/DCD or RTS/CTS would have been a plus; a "real"
serial port with 3/5 signals would of course be even better.

3. While I'm dreaming, I would *love* to see a USB-A or -AB connector
and/or an Ethernet PHY (not a fullblown Ethernet controller) connected
to the FPGA.

That would make the DE1 a dream board in my book.

	-hpa
Try writing directly to TeraSic (either sales or support). I have
gotten good responses from them.

My perpetual request:

4. More Memory Please. You can never have too much, too fast, or too
wide memory.

Tommy




On Nov 30, 2:18=A0am, "H. Peter Anvin" <h...@zytor.com> wrote:
> Hello, > > I am in the process of porting a project of mine from the Cyclone Nios > Development Kit to the Terasic DE1 board. =A0The main reason for this is > to be able to run on less expensive hardware and thus make the project > available to more people (hence "get a better board" is not really an > easy answer.) =A0My interest is mostly in computing projects, so my views > are certainly biased in that direction. > > Unfortunately, I have run into a few issues with the DE1 board. =A0I > thought I'd post them here (and please let me know if there is a better > place to send this) in the hope that a future board (Cyclone III-based, > maybe?) might address these. =A0Please don't get me wrong - this is a > great board at a great price; I think, however, that a few things would > make it even better. > > 1. The SD card slot only connects a handful of signals. =A0In particular, > it does not connect the two switch pins on the socket (card detect and > write protect.) =A0This makes it much harder than it needs to be to handl=
e
> card removal and insertion. > > 2. Similarly, the serial port doesn't connect more than the transmit and > receive signals, even though there is a 2/2 transceiver on the board. > Having at least DTR/DCD or RTS/CTS would have been a plus; a "real" > serial port with 3/5 signals would of course be even better. > > 3. While I'm dreaming, I would *love* to see a USB-A or -AB connector > and/or an Ethernet PHY (not a fullblown Ethernet controller) connected > to the FPGA. > > That would make the DE1 a dream board in my book. > > =A0 =A0 =A0 =A0 -hpa
On Nov 30, 4:18=A0am, "H. Peter Anvin" <h...@zytor.com> wrote:
> Hello, > > I am in the process of porting a project of mine from the Cyclone Nios > Development Kit to the Terasic DE1 board. =A0The main reason for this is > to be able to run on less expensive hardware and thus make the project > available to more people (hence "get a better board" is not really an > easy answer.) =A0My interest is mostly in computing projects, so my views > are certainly biased in that direction. > > Unfortunately, I have run into a few issues with the DE1 board. =A0I > thought I'd post them here (and please let me know if there is a better > place to send this) in the hope that a future board (Cyclone III-based, > maybe?) might address these. =A0Please don't get me wrong - this is a > great board at a great price; I think, however, that a few things would > make it even better. > > 1. The SD card slot only connects a handful of signals. =A0In particular, > it does not connect the two switch pins on the socket (card detect and > write protect.) =A0This makes it much harder than it needs to be to handl=
e
> card removal and insertion. > > 2. Similarly, the serial port doesn't connect more than the transmit and > receive signals, even though there is a 2/2 transceiver on the board. > Having at least DTR/DCD or RTS/CTS would have been a plus; a "real" > serial port with 3/5 signals would of course be even better. > > 3. While I'm dreaming, I would *love* to see a USB-A or -AB connector > and/or an Ethernet PHY (not a fullblown Ethernet controller) connected > to the FPGA. > > That would make the DE1 a dream board in my book. > > =A0 =A0 =A0 =A0 -hpa
The DE1 is a subset of the DE2, which uses almost every single I/O pin on the FPGA. My guess is that they simply deleted portions of the schematic and rerouted the board - which explains some of the oddities you noticed. The upside, however; is that if you ported to the DE2, it should be almost trivial if necessary at all.
radarman wrote:
> The DE1 is a subset of the DE2, which uses almost every single I/O pin > on the FPGA. My guess is that they simply deleted portions of the > schematic and rerouted the board - which explains some of the oddities > you noticed. The upside, however; is that if you ported to the DE2, it > should be almost trivial if necessary at all.
Actually, DE2 fixes some of the worst omissions (e.g. RTS/CTS on RS232), although it still doesn't hook up the sense switches on the SD card socket. The DE2 is truly a superboard, and if it was only in the pricerange of my userbase I'd use it. The lack of sense switches on the SD socket bothers me, mostly because it means that there is no way to honor the write protect tab on a card in the design. -hpa
On Dec 28, 7:48=A0pm, "H. Peter Anvin" <h...@zytor.com> wrote:
> radarman wrote: > > The DE1 is a subset of the DE2, which uses almost every single I/O pin > > on the FPGA. My guess is that they simply deleted portions of the > > schematic and rerouted the board - which explains some of the oddities > > you noticed. The upside, however; is that if you ported to the DE2, it > > should be almost trivial if necessary at all. > > Actually, DE2 fixes some of the worst omissions (e.g. RTS/CTS on RS232), > although it still doesn't hook up the sense switches on the SD card > socket. =A0The DE2 is truly a superboard, and if it was only in the > pricerange of my userbase I'd use it. > > The lack of sense switches on the SD socket bothers me, mostly because > it means that there is no way to honor the write protect tab on a card > in the design.
Both the switches and the extra RS-232 (EIA-232) signals can be wired by the user. I have done this before on other development boards. It is nice if you have a precise drill tool for drilling out vias, but if you can cut traces instead, that works just as well. Otherwise it is just a matter of being familiar with a soldering iron, no? How much is a DE1 board? Rick
rickman wrote:
> > Both the switches and the extra RS-232 (EIA-232) signals can be wired > by the user. I have done this before on other development boards. It > is nice if you have a precise drill tool for drilling out vias, but if > you can cut traces instead, that works just as well. Otherwise it is > just a matter of being familiar with a soldering iron, no? > > How much is a DE1 board? >
$150 ($125 for students.) Again, modding the board is one of those things that is easy to do for oneself, but expecting others to do it is iffier. In this case, it's not even all that hard... the SD socket is pretty well exposed, and one can simply wire the pins up to a pair of pins on the GPIO header. -hpa
On Dec 29, 1:15 am, "H. Peter Anvin" <h...@zytor.com> wrote:
> rickman wrote: > > > Both the switches and the extra RS-232 (EIA-232) signals can be wired > > by the user. I have done this before on other development boards. It > > is nice if you have a precise drill tool for drilling out vias, but if > > you can cut traces instead, that works just as well. Otherwise it is > > just a matter of being familiar with a soldering iron, no? > > > How much is a DE1 board? > > $150 ($125 for students.) Again, modding the board is one of those > things that is easy to do for oneself, but expecting others to do it is > iffier. > > In this case, it's not even all that hard... the SD socket is pretty > well exposed, and one can simply wire the pins up to a pair of pins on > the GPIO header.
Just a brief comment. I am sure you have looked at a number of boards and found many that are much more expensive. $150 is not really a bargain however. Is there something that is "special" about this board or is it just that it is the best combination of features you need at the lowest price point you can find? I certainly don't have anything to suggest that would be cheaper with the same features. Mostly the price of this sort of product is set by the volume. For example Avnet offers a Spartan 3A board at $40. It doesn't have all the features that the DE1 does. I am sure the low price is a result of (and a factor in) very high sales volumes relatively speaking. There may be inexpensive add-on cards that would provide the features you need. Or perhaps the add-on card could be a do-it-yourself module based on perf board? The Avnet AES-SP3A-EVAL400- G does not include RAM, but does support parallel and serial Flash. Care to list all of the features you need? Rick