Altera Integer Arithmetic IP Manuel d'utilisateur télécharger pdf (Page 140)

xy_real = ac – bd

= ac – bd + (ad – bc) – (ad – bc)

= (ac – ad + bc – bd) + (ad – bc)

= ((a + b)(c – d)) + (ad – bc)

xy_real represents the real part

The following equation shows that the xy_imaginary variable represents imaginary representation.

xy_imaginary = ad + bc

xy_imaginary represents imaginary

Both equations derived from Complex Multiplication equation.

Note: The canonical representation is available for all supported Altera devices prior to Stratix III devices.

Related Information

Complex Multiplication on page 10-2

Conventional Representation

The multiplication of two complex numbers can be represented in two parts, real and imaginary. The

xy_real variable in the following equation represents the real part:

xy_real = ac – bd

The xy_imaginary variable in the following equation represents the imaginary part.

xy_imaginary = ad + bc

Features

The ALTMULT_COMPLEX megafunction offers the following features:

• Generates a multiplier to perform multiplication operations of two complex numbers

Note:

When building multipliers larger than the natively supported size there may/will be a perform‐

ance impact resulting from the cascading of the DSP blocks.

• Supports data width of 1–256 bits

• Supports signed and unsigned data representation format

• Supports canonical and conventional implementation modes

• Supports pipelining with configurable output latency

• Supports optional asynchronous clear and clock enable input ports

• Provides an option to dynamically switch between 36 × 36 normal mode and 18 × 18 complex mode

(for Stratix V devices only)

UG-01063

2014.12.19

Conventional Representation

10-3

ALTMULT_COMPLEX (Complex Multiplier)

Altera Corporation

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Altera Integer Arithmetic IP Manuel d'utilisateur Page 140