Spezielle Anwendungen des VLSI –
Entwurfs
Applied VLSI design
Differences between FPGA and
ASIC
René Romann
Institute of Applied Microelectronics and Computer Engineering
College of Computer Science and Electrical Engineering, University of Rostock
Slide 1
Overview
1. FPGA vs. ASIC
2. Usage fields
3. Prices
4. Performance differences (on carry-propagate-adders)
5. Summary
Institute of Applied Microelectronics and Computer Engineering
College of Computer Science and Electrical Engineering, University of Rostock
Slide 2
1. FPGA vs. ASIC
FPGA
•
FPGA consists of Slices
•
Slice contains LUTs
AND Registers
•
Slices connected via
Interconnection network
(wires & switches)
Institute of Applied Microelectronics and Computer Engineering
College of Computer Science and Electrical Engineering, University of Rostock
Slide 3
1. FPGA vs. ASIC
FPGA
ASIC
•
FPGA consists of Slices
•
Contains standard cells
•
Slice contains LUTs
AND Registers
•
Cells operate as logic OR
register
•
Slices connected via
Interconnection network
(wires & switches)
•
Cells connected directly via
wires (no switching)
Institute of Applied Microelectronics and Computer Engineering
College of Computer Science and Electrical Engineering, University of Rostock
Slide 4
2. Usage fields
FPGA
ASIC
•
For testing series
•
For field production
•
Cheaper for small series
•
Cheap if built in mass
•
Can be reprogrammed if
faulty logic was loaded
•
No reprogramming possible
Faulty logic  waste
Institute of Applied Microelectronics and Computer Engineering
College of Computer Science and Electrical Engineering, University of Rostock
Slide 5
3. Prices
FPGA
ASIC
Pricing depends on no. of logic •
cells and interconnections:
• 238 Cells:
$8.68 [2]
• Virtex5 with 5,455,872 RAM
bits:
$1,576.00 [3] •
• Virtex6 with 26,542,080
RAM bits: $23,237.50 [4]
• Virtex7 [not released yet]:
$54,492.65 [5] •
Pricing depends on chip
size, no. of gates, no. of
layers, technology size
Masks for chip production
on a wafer cost more than
$500.000 [6]
Additional costs for wafer,
process…
Institute of Applied Microelectronics and Computer Engineering
College of Computer Science and Electrical Engineering, University of Rostock
Slide 6
4. Performance differences
FPGA mostly slower than ASIC due to:
• Slice/CLB interconnection
• Slice distribution
But:
• FPGA can contain speed-up resources
e.g. Virtex5 – Carry path (compare picture [1])
Institute of Applied Microelectronics and Computer Engineering
College of Computer Science and Electrical Engineering, University of Rostock
Slide 7
4. Performance differences – 32bit adders
Speed
FPGA
ASIC
Ripple Carry adder
251.446 MHz
@ 193 LUT/FF-Pairs
269.469 MHz
@ 154 LUT/FF-Pairs
750 MHz
@ 1621 µm²
PLeak = 488.276 nW
Pdyn = 400.304 µW
Carry-Lookahead-adder
(4-4-4-4-4-4-4-4)
251.446 MHz
@ 195 LUT/FF-Pairs
269.469 MHz
@ 166 LUT/FF-Pairs
950.6 MHz
@ 1625 µm²
PLeak = 399.326 nW
Pdyn = 508.658 µW
Carry-Lookahead-adder
(1-2-3-4-5-6-5-3-2-1)
245.278 MHz
@ 186 LUT/FF-Pairs
271.739 MHz
@ 156 LUT/FF-Pairs
2000 MHz
@ 1807 µm²
PLeak = 1.226 µW
Pdyn = 1.137 mW
Institute of Applied Microelectronics and Computer Engineering
College of Computer Science and Electrical Engineering, University of Rostock
Slide 8
5. Summary
•
FPGA for testing and small applications
•
ASIC for mass production
•
FPGA mostly slower than ASIC
•
ASICs have less power consumption
Institute of Applied Microelectronics and Computer Engineering
College of Computer Science and Electrical Engineering, University of Rostock
Slide 9
Sources
[1]
Slice-Pictures from Virtex 5, Virtex 5 User Guide, Xilinx, p. 174ff
http://www.xilinx.com/support/documentation/user_guides/ug190.pdf
[2]
Price for single SpartanXL chip XCS05XL-4VQG100C, avnet.com
http://avnetexpress.avnet.com/store/em/EMController/FPGA/Xilinx/XCS05XL4VQG100C/_/R-1484451/A-1484451/An-0?action=part&catalogId=500201&langId=1&storeId=500201&listIndex=-1
[3]
Price for single FPGA chip – Virtex 5 XC5VFX70T-1FFG1136I, avnet.com
http://avnetexpress.avnet.com/store/em/EMController/FPGA/Xilinx/XC5VFX70T1FFG1136I/_/R-8245104/A-8245104/An-0?action=part&catalogId=500201&langId=1&storeId=500201&listIndex=-1
[4]
Price for single FPGA chip – Virtex 6 XC6VLX760-L1FF1760I, avnet.com
http://avnetexpress.avnet.com/store/em/EMController/FPGA/Xilinx/XC6VLX760L1FF1760I/_/R-12848106/A-12848106/An0?action=part&catalogId=500201&langId=-1&storeId=500201&listIndex=-1
[5]
Price for single FPGA chip – Virtex 7 XC7VX1140T-G2FL1933E, avnet.com
http://avnetexpress.avnet.com/store/em/EMController/Xilinx/XC7VX1140TG2FL1933E/_/R-5002609600522/A-5002609600522/An0?action=part&catalogId=500201&langId=-1&storeId=500201&listIndex=-1
Institute of Applied Microelectronics and Computer Engineering
College of Computer Science and Electrical Engineering, University of Rostock
Slide I
Sources
[6]
Kosten pro Wafer, Abb. 4.36; Nanotechnologie, Bundesamt für Sicherheit in der
Informationstechnik, 2007,
https://www.bsi.bund.de/SharedDocs/Downloads/DE/BSI/Publikationen/Studien/Nano
technologie/Nanotechnologie_pdf.pdf?__blob=publicationFile
Institute of Applied Microelectronics and Computer Engineering
College of Computer Science and Electrical Engineering, University of Rostock
Slide II