Altera Integer Arithmetic IP - Manual (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
Send Feedback