EP3SE50F780I3N Altera, EP3SE50F780I3N Datasheet - Page 109

• Manufacturer Part Number: EP3SE50F780I3N
• Description: Stratix III
• Manufacturer: Altera

Operational
Modes Overview
Altera Corporation
October 2007
Notes to
(1)
(2)
(3)
(4)
Four-Multiplier
Two-Multiplier
Table 5–2. Stratix III DSP Block Operation Modes
Independent
Accumulate
Multiplier
Adder(1)
Shift
Multiply
Adder
Mode
This mode also supports the loopback mode. In loopback mode, the number of loopback multipliers per DSP block
is two and the remaining multipliers can be used in regular Two-Multiplier Adder mode.
The dynamic shift mode supports arithmetic shift left, arithmetic shift right, logical shift left, logical shift right, and
rotation operation.
The dynamic shift mode operates on a 32-bit input vector but the multiplier width is configured as 36-bits.
Unsigned value is also supported but you must make sure that the result can be contained within 36-bits.
(2)
Table
5–2:
Multiplier
36-bits
in Width
Double
12-bits
18-bits
36-bits
18-bits
18-bits
18-bits
9-bits
(3)
Each Stratix III DSP block can be used in one of five basic operational
modes.
of multipliers that can be implemented within a single DSP block,
depending on the mode.
The DSP block consists of two identical halves (top-half and bottom-half).
Each half has four 18 × 18 multipliers.
The Quartus
mode of operation of the multipliers. After making the appropriate
parameter settings using the megafunction’s MegaWizard
Manager, the Quartus II software automatically configures the DSP
block.
Stratix III DSP blocks can operate in different modes simultaneously.
Each Half-block is fully independent except for the sharing of the four
clock, ena, and aclr signals. For example, you can break down a single
DSP block to operate a 9 × 9 multiplier in one Half-Block and an 18 × 18
Mults
# of
1
1
1
1
1
2
4
4
1
Table 5–2
Block
# per
8
6
4
2
2
4
2
2
2
®
II software includes megafunctions used to control the
Signed
Signed or
Unsigned
shows the five basic operational modes and the number
Both
Both
Both
Both
Both
Both
Both
Both
(4)
RND,
SAT
Yes
Yes
Yes
Yes
No
No
No
No
No
Register
In Shift
Stratix III Device Handbook, Volume 1
Yes
Yes
Yes
No
No
No
No
No
No
DSP Blocks in Stratix III Devices
Chainout
Adder
Yes
Yes
No
No
No
No
No
No
—
Add/Sub
Stage
Both
Both
Both
1st
—
—
—
—
—
—
®
Plug-In
Add/Acc
Stage
Only
Both
Add
2nd
N/A
—
—
—
—
—
—
5–9