Jens Hahne, Hongrui Deng, Arne D¨oring, Daniele Mele
1 FPGA Architecture
Overview
1 Pre-fabricated silicon devices electrically programmable
2 Ad/dis-advantages to Application Specific Integrated Circuit (ASIC)
technologies:
3 From small enterprises to large corporations FPGAs is the only
and multiplier blocks
2 Programmable routing fabric for interconnection
1 FPGA Architecture
Overview
Logic Block Architecture
Logic Block Architecture
1 What is Logic Block Architecture?
2 Categories of Logic Block Architecture
Logic Block Architecture
1 What is Logic Block Architecture?
2 Categories of Logic Block Architecture
What is Logic Block Architecture?
1 A logic Block is the basic functional unit of the FPGA
2 Capable of implementing many different combinational and sequential
logic functions
3 Consist of some combination of these basic functional units: Transistor pairs
Basic small gates (such as two-input NAND’s or exclusive-OR’s) Multiplexers
Logic Block Architecture
1 What is Logic Block Architecture?
2 Categories of Logic Block Architecture
Categories of Logic Block Architecture
1 fine-grain
Categories of Logic Block Architecture
1 fine-grain
consists of just a couple transistors, a couple logic gates like two-input NAND gate.
Such as, The Plessey FPGA uses two-input NAND gate as its basic block.
Figure: The Plessey logic block.[1]
2 coarse-grain
consists of fairly large logic blocks, often containing multiplexer, look-up tables(LUT), or flip-flops.
Logic Block Architecture
1 What is Logic Block Architecture?
2 Categories of Logic Block Architecture
Taking a logic function f = ab + c as an example,
using two-input NAND gate:
Figure: Two-input NAND gate implementation.[1]
using LUT:
1 FPGA Architecture
Overview
Logic Block Architecture
Routing Architecture
Provides communications among Configurable Logic Blocks(CLB) and I/O units
Global routing
Macroscopic allocation of wires Interconnection of CLBs
More predictable inter-logic block delay
Example
1 FPGA Architecture
Overview
Logic Block Architecture Routing Architecture
Input / Output Architecture
I/O cells includes I/O pad and surrounding supporting logic and circuitry
1 FPGA Architecture
Overview
Logic Block Architecture Routing Architecture Input / Output Architecture
FPGA CPU
-No fixed hardware structure -Fixed hardware structure
(fixed: logic cells (peripheral structures, connections,
not fixed: function, interconnection) operation predefine)
-Control over the hardware -Control over the software
-Hardware Description Language -C, Java, ....
-Good for: -Good for:
Johathan Rose, Abbas El Gamal and Alberto Sangiovanni (1993)
[1] Architecture of Field-Programmable Gate Arrays
http://fpgacenter.com/fpga/fpga or cpu.php
Overview (FPGA 1)
Logic Block Architecture (Hongrui Deng) Routing Architecture (FPGA 1)
