13 Nov
2011
13 Nov
'11
6:40 p.m.
On 11/13/2011 8:53 PM, David Riley wrote:
I can vouch for the Terasic DE0 and pretty much agree with most of the
comments. I think the board is a nice board, has PS/2, VGA (with 12-bit
color, nice), SD memory slot, and so on. It uses IDC-40 hard drive
style connectors for the I/O, which there are 72 spare connections.
I agree that writing VGA controllers and serial port UARTs are a great
introduction.
Memory controllers can be a real pain in the ass, and just getting a
free (or included) one working on any board can be more than trivial.
Xilinx's coregen memory generator sucks (for a different board). It
generates huge amounts of code to drive DDR memory in an overly complex
fashion.
I found a FOSS memory controller for the altera terasic DE0 board, and
it works like a charm.
I've created a simple frame buffer application where I can upload via a
USB<->LVTTL converter a properly formatted image into the SDRAM on the
board and then it displays it on a monitor.
youtube video for anyone so inclined......
http://www.youtube.com/watch?v=CGLbEd44MoA
I'm in the process of getting code etc online for this.
Keith
The board has VGA,serial ,SDRAM that have to be
programed for use.
I would have to re-event the wheel to recreate the design the
hardware is programed with. A nice 6809B computer is looking better
and better.
You don't have to program anything you don't want to use. Besides,
developing a simple serial port or VGA controller is a great way to
introduce yourself to digital design, whether on an FPGA or with
discrete logic. A DRAM controller is a good next step (hint: an SDRAM
controller isn't much more complex than a DRAM controller).
Reinventing the wheel is half the fun sometimes; in comparison to a
CPU of any complexity the above examples are small potatoes.
- Dave