Learning VHDL on VHDL CPLD Course

[PeeweePete]

I found this rather nice VHDL course for learning VHDL on a CPLD http://startingelectronics.com/software/VHDL-CPLD-course/

You can actually build the hardware yourself at home and then follow the course. There are no SMT parts on the boards. 
According to the Blog entry on the website(http://blog.startingelectronics.com/?p=428), the course is not complete. (It looks like it is being added to weekly).

So who is going to join me and follow the course? 

(BTW I discovered this course after looking around the website that published the radio controlled watermelon http://startingelectronics.com/articles/radio-controlled-watermelon/) 

[mrflibble]

More of a verilog person myself, but I really love the watermelon! XD

[Wilksey]

Good find!  I shall certainly be looking at it, i've done a bit with modifying other people's code, but I always find it good to get a refresher!

[djsb]

AND the board files are done on Kicad. Fantastic. I will be building this over the summer for certain.

David.

[PeeweePete]

It looks like Xilinx and Altera are the two biggest vendors of programmable logic chips (CPLD / FPGA). Does anyone have any preference?

[Kremmen]

I have used Xilinx CoolRunner II CPLDs. Mostly because i am more familiar with the Xilinx ISE design suite than Altera's Quartus.
But also because the CoolRunner is a quite nice chip series with several macrocell sizes and multiple I/O banks allowing different logic voltage levels.

Note that the project you linked in the original post, the device is an older XC9500 series CPLD. Those have only 36 macrocells (at least the ones you can actually get from DK), while CoolRunners go up to 512 macrocells if necessary. Maybe not important but worth mentioning, perhaps.

[notsob]

And you can get a coolrunner II dev board for $15

http://www.seeedstudio.com/depot/xc2c64a-coolrunnerii-cpld-development-board-p-800.html

[andersm]

Note that the project you linked in the original post, the device is an older XC9500 series CPLD. Those have only 36 macrocells (at least the ones you can actually get from DK), while CoolRunners go up to 512 macrocells if necessary.

XC9500XL to be precise (the other XC9500 series have been obsoleted), and they go up to 288 macrocells. They still have the advantage of 5V-tolerant IO.

And you can get a coolrunner II dev board for $15

http://www.seeedstudio.com/depot/xc2c64a-coolrunnerii-cpld-development-board-p-800.html

That's one of Dangerous Prototypes' designs, they also have a 72-macrocell XC9500XL board for the same price.

[Kremmen]

OK, i stand corrected. Not really familiar with the 9500s, so my mistake. I thought they were all nearly obsolete but apparently not so.

[nctnico]

The XC9500XL series is pretty nifty. They are 5V tolerant and run from a 3.3V supply. I have used the PLCC versions on veroboard as well. In a recent project I've used the 144 macrocell version to capture the data from an STN display interface, build new image data in an external SRAM and display it on a TFT screen.

BTW Xilinx USB programming adapters are dirt cheap on Ebay:
http://www.ebay.com/itm/Xilinx-Platform-Cable-USB-CPLD-FPGA-USB-download-cable-/120988562867

[PeeweePete]

Thanks for the info on those cheap boards. 

I must decide whether or not to build the CPLD board or buy a cheap board. The only problems that I see if buying a board is that they do not have the LEDs and switches that are needed for the VHDL course which is a bit of a hassle to have to hook them up to a breadboard or whatever.

I see that the home made board is using an AVR for a clock source (http://startingelectronics.com/projects/xilinx-CPLD-board/). Can anyone see if the seeed boards have a clock source? I can't see any clock source from the description.

[notsob]

The seeedstudio boards do not come with an oscillator, but there is provision on the underside of the board to fit one, the suggested ones are 20MHz and 50MHz

http://no.mouser.com/ProductDetail/ABRACON/ASV-50000MHZ-EJ-T/?qs=H8AWquzS/lOR%252bU4UILwQkw==
http://no.mouser.com/ProductDetail/ABRACON/ASV-20000MHZ-EJ-T/?qs=H8AWquzS/lNowiZ9Nk9Uyw==

[andersm]

Both of those two boards are open-source designs, and the full project details are available on Dangerous Prototypes' website.