MultiTrack Interconnect
A LAB-wide asynchronous load signal to control the logic for the
register’s preset signal is not available. The register preset is achieved by
using a NOT gate push-back technique. Cyclone II devices can only
support either a preset or asynchronous clear signal.
In addition to the clear port, Cyclone II devices provide a chip-wide reset
pin (DEV_CLRn) that resets all registers in the device. An option set before
compilation in the Quartus II software controls this pin. This chip-wide
reset overrides all other control signals.
In the Cyclone II architecture, connections between LEs, M4K memory
blocks, embedded multipliers, and device I/O pins are provided by the
MultiTrack interconnect structure with DirectDrive™ technology. The
MultiTrack interconnect consists of continuous, performance-optimized
routing lines of different speeds used for inter- and intra-design block
connectivity. The Quartus II Compiler automatically places critical paths
on faster interconnects to improve design performance.
MultiTrack
Interconnect
DirectDrive technology is a deterministic routing technology that ensures
identical routing resource usage for any function regardless of placement
within the device. The MultiTrack interconnect and DirectDrive
technology simplify the integration stage of block-based designing by
eliminating the re-optimization cycles that typically follow design
changes and additions.
The MultiTrack interconnect consists of row (direct link, R4, and R24) and
column (register chain, C4, and C16) interconnects that span fixed
distances. A routing structure with fixed-length resources for all devices
allows predictable and repeatable performance when migrating through
different device densities.
Row Interconnects
Dedicated row interconnects route signals to and from LABs, PLLs, M4K
memory blocks, and embedded multipliers within the same row. These
row resources include:
■
■
■
Direct link interconnects between LABs and adjacent blocks
R4 interconnects traversing four blocks to the right or left
R24 interconnects for high-speed access across the length of the
device
2–10
Altera Corporation
February 2007
Cyclone II Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
