EP2C20F256C6N Altera, EP2C20F256C6N Datasheet - Page 16

• Manufacturer Part Number: EP2C20F256C6N
• Description: IC CYCLONE II FPGA 20K 256-FBGA
• Manufacturer: Altera
• Series: Cyclone® IIr

Specifications of EP2C20F256C6N

• Number Of Logic Elements/cells: 18752
• Number Of Labs/clbs: 1172
• Total Ram Bits: 239616
• Number Of I /o: 152
• Voltage - Supply: 1.15 V ~ 1.25 V
• Mounting Type: Surface Mount
• Operating Temperature: 0°C ~ 85°C
• Package / Case: 256-FBGA
• For Use With: P0528 - BOARD DEV DE1 ALTERA544-1736 - CYCLONE II STARTER KIT EP2C20N
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of Gates: -
• Other names: 544-1660

Logic Elements
2–4
Cyclone II Device Handbook, Volume 1
Another special packing mode allows the register output to feed back into
the LUT of the same LE so that the register is packed with its own fan-out
LUT, providing another mechanism for improved fitting. The LE can also
drive out registered and unregistered versions of the LUT output.
In addition to the three general routing outputs, the LEs within an LAB
have register chain outputs. Register chain outputs allow registers within
the same LAB to cascade together. The register chain output allows an
LAB to use LUTs for a single combinational function and the registers to
be used for an unrelated shift register implementation. These resources
speed up connections between LABs while saving local interconnect
resources. See
information on register chain connections.
LE Operating Modes
The Cyclone II LE operates in one of the following modes:
■
■
Each mode uses LE resources differently. In each mode, six available
inputs to the LE—the four data inputs from the LAB local interconnect,
the LAB carry-in from the previous carry-chain LAB, and the register
chain connection—are directed to different destinations to implement the
desired logic function. LAB-wide signals provide clock, asynchronous
clear, synchronous clear, synchronous load, and clock enable control for
the register. These LAB-wide signals are available in all LE modes.
The Quartus
such as library of parameterized modules (LPM) functions, automatically
chooses the appropriate mode for common functions such as counters,
adders, subtractors, and arithmetic functions. If required, you can also
create special-purpose functions that specify which LE operating mode to
use for optimal performance.
Normal Mode
The normal mode is suitable for general logic applications and
combinational functions. In normal mode, four data inputs from the LAB
local interconnect are inputs to a four-input LUT (see
Quartus II Compiler automatically selects the carry-in or the data3
signal as one of the inputs to the LUT. LEs in normal mode support
packed registers and register feedback.
Normal mode
Arithmetic mode
®
II software, in conjunction with parameterized functions
“MultiTrack Interconnect” on page 2–10
Figure
Altera Corporation
for more
February 2007
2–3). The