MAX 3000A Programmable Logic Device Family Data Sheet
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 eight, the lowest-numbered macrocell
can only lend parallel expanders and the highest-numbered macrocell can
only borrow them.
Figure 4
shows how parallel expanders can be
borrowed from a neighboring macrocell.
Figure 4. MAX 3000A Parallel Expanders
Unused product terms in a macrocell can be allocated to a neighboring macrocell.
from
Previous
Macrocell
Preset
Product-
Term
Select
Matrix
Clock
Clear
Macrocell
Product-
Term Logic
Preset
Product-
Term
Select
Matrix
Clock
Clear
Macrocell
Product-
Term Logic
36 Signals
from PIA
16 Shared
Expanders
to Next
Macrocell
Altera Corporation
9
ETC [ ETC ]
