Digital Signal Processing Block
The most commonly used DSP functions are FIR filters, complex FIR
Digital Signal
Processing
Block
filters, IIR filters, fast Fourier transform (FFT) functions, direct cosine
transform (DCT) functions, and correlators. All of these use the multiplier
as the fundamental building block. Additionally, some applications need
specialized operations such as multiply-add and multiply-accumulate
operations. Stratix II devices provide DSP blocks to meet the arithmetic
requirements of these functions.
Each Stratix II device has from two to four columns of DSP blocks to
efficiently implement DSP functions faster than ALM-based
implementations. Stratix II devices have up to 24 DSP blocks per column
(see Table 2–5). Each DSP block can be configured to support up to:
■
■
■
Eight 9 × 9-bit multipliers
Four 18 × 18-bit multipliers
One 36 × 36-bit multiplier
As indicated, the Stratix II DSP block can support one 36 × 36-bit
multiplier in a single DSP block. This is true for any combination of
signed, unsigned, or mixed sign multiplications.
1
This list only shows functions that can fit into a single DSP block.
Multiple DSP blocks can support larger multiplication
functions.
2–40
Altera Corporation
May 2007
Stratix II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
