Altera Stratix - Operational Modes; Simple Multiplier Mode

6–18 Altera Corporation
Stratix Device Handbook, Volume 2 July 2005
Operational Modes
The row interface block has DirectLink™ connections that connect the
DSP block input or output signals to the left and right adjacent LABs at
each row. (The DirectLink connections provide interconnects between
LABs and adjacent blocks.) The DirectLink connection reduces the use of
row and column interconnects, providing higher performance and
flexibility.
Each row interface block receives 10 DirectLink connections from the
right adjacent LABs and 10 from the left adjacent LABs. Additionally, the
row interface block receives signals from the DSP block, making a total of
30 local interconnects for each row interface block. All of the row and
column resources within the DSP block can access this interconnect
region (see Figure 6–7 on page 6–14).
A DSP block has nine outputs that drive the right adjacent LAB and nine
that drive the left adjacent LAB through DirectLink interconnects. All
18 outputs drive any row or column.
Operational
Modes
You can use the DSP block in one of four operational modes, depending
on your application needs (see Table 6–4). The Quartus II software has
built-in megafunctions that you can use to control the mode. After you
have made your parameter settings using the megafunction’s
MegaWizard
®
Plug-In, the Quartus II software automatically configures
the DSP block.
Simple Multiplier Mode
In simple multiplier mode, the DSP block performs individual
multiplication operations for general-purpose multipliers and for
applications such as equalizer coefficient updates that require many
individual multiplication operations.
Table 6–5. DSP Block Operational Modes
Mode 9 × 9 18 × 18 36 × 36
Simple multiplier Eight multipliers with eight
product outputs
Four multipliers with four
product outputs
One multiplier
Multiply accumulator Two 34-bit multiply-
accumulate blocks
Two 52-bit multiply-
accumulate blocks
–
Two-multiplier adder Four two-multiplier adders Two two-multiplier adders –
Four-multiplier adder Two four-multiplier adders One four-multiplier adder –