MAX 9000 Programmable Logic Device Family Data Sheet
The MAX+PLUS II Compiler automatically allocates as many as three sets
of up to five parallel expanders to macrocells that require additional
product terms. Each set of expanders incurs a small, incremental timing
delay (tPEXP). For example, if a macrocell requires 14 product terms, the
Compiler uses the five dedicated product terms within the macrocell and
allocates two sets of parallel expanders; the first set includes five product
terms and the second set includes four product terms, increasing the total
delay by 2 × tPEXP
.
Two groups of eight macrocells within each LAB (e.g., macrocells 1
through 8 and 9 through 16) form two chains to lend or borrow parallel
expanders. A macrocell borrows parallel expanders from lower-
numbered macrocells. For example, macrocell 8 can borrow parallel
expanders from macrocell 7, from macrocells 7 and 6, or from macrocells
7, 6, and 5. Within each group of 8, the lowest-numbered macrocell can
only lend parallel expanders and the highest-numbered macrocell can
only borrow them.
FastTrack Interconnect
In the MAX 9000 architecture, connections between macrocells and device
I/ O pins are provided by the FastTrack Interconnect, a series of
continuous horizontal and vertical routing channels that traverse the
entire device. This device-wide routing structure provides predictable
performance even in complex designs. In contrast, the segmented routing
in FPGAs requires switch matrices to connect a variable number of
routing paths, increasing the delays between logic resources and reducing
performance. Figure 6 shows the interconnection of four adjacent LABs
with row and column interconnects.
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Altera Corporation
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