How to make right selection between FPGA and DSP

FPGA is an electronic device that helps the design engineers to create custom logic for high commutation signal processing and DSP is a CPU for signal processing applications that has been designed to execute signal processing algorithms for which the principle algorithm that is multiply-and-accumulate operation is similar to all other algorithms. In the implementation of DSP (Digital Signal Processor) and FPGA (Field Programmable Gate Array), design engineers focus on various parameters such as: Power Consumption, System Performance, Form Factor, System"s Future Upgrade Ability, Non-Recurring Engineering (NRE) Investment, Bill-of-Materials (BOM) Cost and Project Risk. Generally the engineers know about DSP but not completely aware of FPGA and hence this creates a situation where they need to select any one of them.

These devices are very different from each other and designed to serve different purposes. DSP provide an optimized platform for signal processing algorithms implemented in software whereas FPGA were for glue logic. Nowadays, there are certain applications where both these devices deliver optimum solutions. FPGA is the better choice for networking applications and DSP is at its best in video applications. This example indicates their performance has gone through a remarkable change over the years.

In terms of cost-performance values, DSP and FPGA are compared in three MMAC (Millions of Multiply-Accumulate Operations per Second) performance categories viz. High, Medium and Low.
MMAC is the number of fixed-point-32-bit or single-precision floating-point multiply-and-accumulate operations that can be executed in units of millions per second. The table given below can help the design engineers in making the right selection between DSP and FPGA.


MMAC Category
Device Cost Range
Minimum Cents/MMAC for FPGA
Minimum Cents/MMAC for DSP
High (>1000 MMAC)
$100 to $300
2.9
5.8
$300 to $1000
4.2
13.4
$1000 to $10000
20
-
Medium (300 to 1000 MMAC)
$10 to $30
1.4
1.6
$30 to $100
2.8
3
Low (