• USING THE VIDEO INPUT PORT ON THE XST-3.0 BOARD
• DESIGN FILES
• USING THE DESIGN EXAMPLE
• ENVIRONMENT
• SOURCE FILES
• AUTHOR
• COPYRIGHT AND LICENSE
• HISTORY

USING THE VIDEO INPUT PORT ON THE XST-3.0 BOARD

This is a simple design to grab frames of video data and display them on a VGA monitor.

DESIGN FILES

• common.vhd
  
This file contains some definitions and functions used in the rest of the VHDL code.
• sdramcntl.vhd
  
This VHDL file describes a controller that simplifies writing/reading data to/from an SDRAM.
• xsasdramcntl.vhd
  
This VHDL file surrounds the generic SDRAM controller with a wrapper that customizes it for the XSA Boards.
• fifo.vhd
  
This file contains concise VHDL descriptions of the synchronous and asynchronous FIFOs described in Xilinx application note XAPP131.
• framegrabber.vhd
  
This VHDL file describes a simple state machine that accepts pixels from a video decoder and places them in a FIFO buffer.
• vga.vhd
  
This VHDL file describes a controller that accepts a stream of pixels and displays them on a VGA monitor.
• video.vhd
  
This VHDL file ties the previous modules together to form a complete frame grabber application. When a button is pressed, the video codec dumps a stream of pixels in ITU-R BT.656 format, 8-bit 4:2:2 with embedded syncs to the framegrabber module using a sampling clock of 27 MHz. The framegrabber loads the pixels into a FIFO (along with some framing information). A finite-state machine (FSM) offloads the pixels from the FIFO at 50 MHz and stores the pixels into SDRAM while interleaving the lines of video from the odd and even fields. Another address counter is used to read stored pixels from the SDRAM at 50 MHz and load them into a FIFO. The VGA generator retrieves pixels from this FIFO and displays them on a monitor.  __________                                                                                    
|          |    _________      ______________                                                  
| Parallel |   |         |    |              |     __________                                  
|   Port   |   | Button  |    | Address Cntr |    |          |                                 
|__________|   |_________|    |    + FSM     |--->|          |                                 
     |              |         |______________|    |          |                                 
     |              |                             |          |                                 
 ____V____      ____V____      ______________     |          |      ____________       _______ 
|         |    |         |    |              |    |          |     |            |     |       |
|  Video  |--->|  Frame  |--->|     FIFO     |--->|          |     |            |     |       |
|  Codec  |    | Grabber |    |______________|    |          |     |            |     |       |
|_________|    |_________|                        |          |     |   SDRAM    |     |       |
                                                  | Dualport |<--->| Controller |<--->| SDRAM |
 _________      _________      ______________     |          |     |            |     |       |
|         |    |         |    |              |    |          |     |            |     |       |
| Monitor |<---|   VGA   |<---|     FIFO     |<---|          |     |            |     |       |
|_________|    |_________|    |______________|    |          |     |____________|     |_______|
                                                  |          |                                 
                               ______________     |          |                                 
                              |              |    |          |                                 
                              | Address Cntr |--->|          |                                 
                              |______________|    |__________|                                 

• video.ucf
  
These are the constraints which assign the I/O signals of the video module to the appropriate pins of the FPGA on the XSA-3S1000 + XST-3.0 combination.
• video.bit
  
This is a compiled bitstream for the design that can be downloaded into the XSA-3S1000 + XST-3.0 combination.
• video-200.ucf
  
This is an alternate set of pin assignments to be used if the design is recompiled for an XSA-200 + XST-3.0 combination.
• video.npl
  
Open this project file with WebPACK if you need to recompile the design.
• xsi2c.exe
  
This is a command-line program that allows you to initialize the control registers on the video decoder chip through the parallel port of a PC.

USING THE DESIGN EXAMPLE

• Step 1:
  
Set jumper J9 on the XSA-3S1000 Board to XS.
• Step 2:
  
Download the default parallel port interface into the XSA-3S1000 (\XSTOOLS\XSA\3S1000\dwnldpar.svf) if it is not already present. (Running GXSTEST will do this automatically.)
• Step 3:
  
Download the video.bit file to the XSA Board.
• Step 4:
  
Connect a VGA monitor to the DB15 port (J3) of the XSA-3S1000 Board.
• Step 5:
  
Connect a source of NTSC video to RCA jack AIP1A on the XST-3.0 Board.
• Step 6:
  
Within a command window on the PC, type the command:

  xsi2c -a B8 -scl_out_pin 2 -sda_out_pin 3 -scl_in_pin 15 -sda_in_pin 13 -w 3 6D

This will enable the outputs of the TVP5150 video codec chip.

• Step 7:
  
Press the PB1 button on the XST-3.0 Board. A frame of video from the video source will be captured and displayed on the VGA monitor.

ENVIRONMENT

This example design was developed using the following version of software:

   Xilinx WebPACK       : 6.3.03i

SOURCE FILES

You can download the source files for this example design from the XESS website at http://www.xess.com/projects/xst3_video.zip .

AUTHOR

Dave Vanden Bout, X Engineering Software Systems Corp.

Send bug reports to bugs@xess.com.

COPYRIGHT AND LICENSE

Copyright 2006 by X Engineering Software Systems Corporation.

This application can be freely distributed and modified as long as you do not remove the attributions to the author or his employer.

HISTORY

02/11/2006 - Initial release.