1. Linking Field-Programmable Gate Arrays to LINUX Box
Marcus Baines
Norfolk State University
August 14, 2008
Mentor: Ryan Herbst

2. Contents What are FPGAs? The Pretty Good Protocol(PGP)‏
Raw Ethernet Frames
Replaced MAC Address
The Hardware Interface
The Software Interface
Setup Before the New Code
Setup After the New Code

3. What are FPGAs?
Field-Programmable Gate Arrays are semiconductor devices that contain many programmable logic blocks and programmable interconnects.

4. The Pretty Good Protocol
The PGP supports movement of data across a high-speed communications link over four independent virtual channels.
Each channel appears as a separate set of interface signals to the FPGA hardware and are broken down into transmit and receive signals.

5. Raw Ethernet Frames Bytes 0 to 5: Destination MAC Address
Bytes 6 to 11: Source MAC Address
Bytes 12 and 13: Protocol
Bytes 14 and on: Payload(User) Data

6. Replaced MAC Address Byte 1: Serial(Sequence) Number
Byte 2: Serial Number
Byte 3: Frame Type [Null, Poll, Read, Write]
Byte 4: Virtual Channel and Frame[SOF, EOF, EOFE, Error]
Byte 5: Size of Data
Byte 6: Size of Data

7. The Hardware Interface
Reads Header and makes decision based on frame type.
May pass data onto the user.
May make a read request to retrieve data.
May make an ACK request to a received frame.
Generates the Header of the new outgoing frame.
Places data in required field.

8. The Software Interface
Opens Ethernet link.
Receives and transmits frames to and from the user logic in the FPGA.
If required, breaks data up and sends in multiple frames.

9. Setup Before the New Code
Supports three smaller 64 channel Kpix ASICs

10. Setup After the New Code
Next version of KPIX will contain 1024 channel ASICs.
The new code allows many more devices of a larger density.

11. Acknowledgements References
Special Thank You to Ryan Herbst, Steve Rock, Farah Rahbar, Susan Schultz, and Department of Energy for making this a wonderful experience.
References
Nicolle, Jean P. April What are FPGAs? [Online]. FPGAs 4 Fun
Wikipedia. July Field-Programmable Gate Arrray. [Online]. Wikimedia Foundation, Inc.
Herbst, Ryan. PGP Over Ethernet. PDF. June unpublished.
Pellerin, David and Douglas Taylor. VHDL Made Easy! Prentice Hall PTR, New Jersey