Logic Array Blocks
LAB Interconnects
The LAB local interconnect can drive LEs within the same LAB. The LAB
local interconnect is driven by column and row interconnects and LE
outputs within the same LAB. Neighboring LABs, PLLs, M4K RAM
blocks, and embedded multipliers from the left and right can also drive
an LAB’s local interconnect through the direct link connection. The direct
link connection feature minimizes the use of row and column
interconnects, providing higher performance and flexibility. Each LE can
drive 48 LEs through fast local and direct link interconnects. Figure 2–6
shows the direct link connection.
Figure 2–6. Direct Link Connection
Direct link interconnect from
left LAB, M4K memory
block, embedded multiplier,
PLL, or IOE output
Direct link interconnect from
right LAB, M4K memory
block, embedded multiplier,
PLL, or IOE output
Direct link
interconnect
to right
Direct link
interconnect
to left
Local
Interconnect
LAB
LAB Control Signals
Each LAB contains dedicated logic for driving control signals to its LEs.
The control signals include:
■
■
■
■
■
Two clocks
Two clock enables
Two asynchronous clears
One synchronous clear
One synchronous load
2–8
Cyclone II Device Handbook, Volume 1
Altera Corporation
February 2007
ALTERA [ ALTERA CORPORATION ]
