Stratix Architecture
row connections in a four-LAB region. Every LAB has its own set of R4
interconnects to drive either left or right. Figure 2–9 shows R4
interconnect connections from an LAB. R4 interconnects can drive and be
driven by DSP blocks and RAM blocks and horizontal IOEs. For LAB
interfacing, a primary LAB or LAB neighbor can drive a given R4
interconnect. For R4 interconnects that drive to the right, the primary
LAB and right neighbor can drive on to the interconnect. For R4
interconnects that drive to the left, the primary LAB and its left neighbor
can drive on to the interconnect. R4 interconnects can drive other R4
interconnects to extend the range of LABs they can drive. R4
interconnects can also drive C4 and C16 interconnects for connections
from one row to another. Additionally, R4 interconnects can drive R24
interconnects.
Figure 2–9. R4 Interconnect Connections
Adjacent LAB can
Drive onto Another
LAB's R4 Interconnect
C4, C8, and C16
Column Interconnects (1)
R4 Interconnect
Driving Right
R4 Interconnect
Driving Left
LAB
Neighbor
Primary
LAB (2)
LAB
Neighbor
Notes to Figure 2–9:
(1) C4 interconnects can drive R4 interconnects.
(2) This pattern is repeated for every LAB in the LAB row.
The R8 interconnects span eight LABs, M512 or M4K RAM blocks, or DSP
blocks to the right or left from a source LAB. These resources are used for
fast row connections in an eight-LAB region. Every LAB has its own set
of R8 interconnects to drive either left or right. R8 interconnect
connections between LABs in a row are similar to the R4 connections
shown in Figure 2–9, with the exception that they connect to eight LABs
to the right or left, not four. Like R4 interconnects, R8 interconnects can
drive and be driven by all types of architecture blocks. R8 interconnects
Altera Corporation
July 2005
2–15
Stratix Device Handbook, Volume 1
ALTERA [ ALTERA CORPORATION ]
