A CAD tool for custom magnitude comparators

Paper presentation for PCI2015 conference in Athens, Greece.

Transcript

1. 1 A CAD tool for custom magnitude comparators Ioannis Petrousov petrousov@gmail.com Minas Dasygenis mdasyg@ieee.org Department of Informatics and Telecommunications Engineering University of Western Macedonia, Kozani, Greece
2. 2 Today's Date Outline Outline Introduction Comparator circuit design Our online CAD tool CAD generation modules CAD output files Experimental results Future work
3. 3 Today's Date Introduction Introduction The complexity of modern hardware inhibits the time to market. CAD tools greatly accelerate every step of the design and simulation of hardware. Magnitude comparator is a component found in a plethora arithmetic circuits. Designing one from scratch is a complicated and time consuming procedure.
4. 4 Today's Date Introduction Our proposal-solution
5. 5 Today's Date Comparator circuit design Comparator circuit design Circuit design based on a 1978 patent (US Patent 4,225,849). General N-bit tree design magnitude comparator. Made of fundamental gates (NOT, AND, OR). Input: 2 N-bit input numbers (A and B). Output: 1 three bit one-hot output (G: A>B, E: A=B, L: A<B). Consists of 4 sub-circuits. Sub-circuits are combined together according to the bitwidth of the input numbers.
6. 6 Today's Date Comparator circuit design Subcircuits (1/4) 1-bit comparator. The first component of each comparator. Input: one bit of each number A and B. Output: intermediate signals (need normalization)
7. 7 Today's Date Comparator circuit design Subcircuits (2/4) Trinot intermediate circuit. Input: signals from 1- bit comparator. Output: normalized signals (one-hot format).
8. 8 Today's Date Comparator circuit design Subcircuits (3/4) Type 1 cascading component. Accepts input from two 1-bit comparators. The arrows indicate the origin of each bit. <- left sub-circuit -> right sub-circuit
9. 9 Today's Date Comparator circuit design Subcircuits (4/4) Type 4 cascading component. Accepts input from two type 1 components. The arrows indicate the origin of each bit.
10. 10 Today's Date Comparator circuit design Smallest magnitude comparator 1-bit magnitude comparator. Components: 1-bit comparator + trinot. The output is in one- hot format. G E L input 1 0 0 B>A 0 1 0 B=A 0 0 1 B<A
11. 11 Today's Date Comparator circuit design 5-bit comparator
12. 12 Today's Date Comparator circuit design 8-bit comparator
13. 13 Today's Date Our online CAD tool Our online HDL generator JSON Frontend Backend • HTML • CSS • Javascript • Python • PHP • BASH • Cython
14. 14 Today's Date Our online CAD tool The frontend Online generator for magnitude comparators. Arbitrary bitwidths. Random testbenches. Error free designs. Easy to use.
15. 15 Today's Date Our online CAD tool The backend Design module HDL generator module Testbench generator module
16. 16 Today's Date CAD generation modules Design module Comparator design module. Creates a 3D netlist in an internal format. Operates in three stages. Each stage fills a layer of the comparator with a sub-circuit type.
17. 17 Today's Date CAD generation modules HDL generator module General purpose generator. Accepts the netlist (α- HDL). Defines components and their interconnections.
18. 18 Today's Date CAD generation modules Testbench generator module Generate two random numbers. Drive them to the comparator. Precalculate the correct result. Compare the output with the result.
19. 19 Today's Date • CAD output files • CAD output files log file 3 VHDL files Magnitude comparator code Components library Testbench dot file Schematic PNG file
20. 20 Today's Date • CAD output files Synthesize anywhere • Vendor neutral VHDL codes. • Synthesizable in ASIC or FPGA.
21. 21 Today's Date Experimental results Experiments & metrics • No other tool provides custom magnitude comparator codes. • Synthesized VHDL in Xilinx ISE 13.3 • Virtex6 FPGA family speed grade -2
22. 22 Today's Date Future work Future work Introduce more building block circuits to out generator. Speed optimizations Pipeline all the designs.
23. 23 End of Presentation Any questions? Today's Date End Of Presentation Visit our tool online http://arch.icte.uowm.gr/hdl/