2–8
Chapter 2: MAX V Architecture
Logic Elements
Logic Elements
The smallest unit of logic in the MAX V architecture, the LE, is compact and provides
advanced features with efficient logic utilization. Each LE contains a four-input LUT,
which is a function generator that can implement any function of four variables. In
addition, each LE contains a programmable register and carry chain with carry-select
capability. A single LE also supports dynamic single-bit addition or subtraction mode
that is selected by an LAB-wide control signal. Each LE drives all types of
interconnects: local, row, column, LUT chain, register chain, and DirectLink
interconnects as shown in Figure 2–6.
Figure 2–6. LE for MAX V Devices
Register chain
routing from
previous LE
LAB-wide
Synchronous
Register Bypass
LAB Carry-In
Carry-In1
Load
Programmable
Register
LAB-wide
Synchronous
Packed
Register Select
addnsub
Carry-In0
Clear
LUT chain
routing to next LE
data1
Row, column,
and DirectLink
routing
PRN/ALD
data2
data3
Synchronous
Load and
Clear Logic
Look-Up
Table
(LUT)
Carry
Chain
D
Q
ADATA
data4
ENA
CLRN
Row, column,
and DirectLink
routing
labclr1
labclr2
Asynchronous
Clear/Preset/
Load Logic
Local routing
labpre/aload
Chip-Wide
Reset (DEV_CLRn)
Register chain
output
Register
Feedback
Clock and
Clock Enable
Select
labclk1
labclk2
labclkena1
labclkena2
Carry-Out0
Carry-Out1
LAB Carry-Out
You can configure each LE’s programmable register for D, T, JK, or SR operation. Each
register has data, true asynchronous load data, clock, clock enable, clear, and
asynchronous load/preset inputs. Global signals, general purpose I/O (GPIO) pins,
or any LE can drive the register’s clock and clear control signals. Either GPIO pins or
LEs can drive the clock enable, preset, asynchronous load, and asynchronous data.
The asynchronous load data input comes from the data3input of the LE. For
combinational functions, the LUT output bypasses the register and drives directly to
the LE outputs.
Each LE has three outputs that drive the local, row, and column routing resources. The
LUT or register output can drive these three outputs independently. Two LE outputs
drive either a column or row and DirectLink routing connections while one output
drives the local interconnect resources. This configuration allows the LUT to drive one
output while the register drives another output. This register packing feature
MAX V Device Handbook
December 2010 Altera Corporation
ALTERA [ ALTERA CORPORATION ]
