EPM7256BTC100-10N Altera, EPM7256BTC100-10N Datasheet - Page 10

• Manufacturer Part Number: EPM7256BTC100-10N
• Description: MAX 7000/S/AE/B
• Manufacturer: Altera

Specifications of EPM7256BTC100-10N

• Rohs Compliant: YES

MAX 7000B Programmable Logic Device Data Sheet
10
Parallel Expanders
Parallel expanders are unused product terms that can be allocated to a
neighboring macrocell to implement fast, complex logic functions.
Parallel expanders allow up to 20 product terms to directly feed the
macrocell OR logic, with five product terms provided by the macrocell and
15 parallel expanders provided by neighboring macrocells in the LAB.
The Altera Compiler can automatically allocate up to three sets of up to
five parallel expanders to the macrocells that require additional product
terms. Each set of five parallel expanders incurs a small, incremental
timing delay (t
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 × t
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.
borrowed from a neighboring macrocell.
PEXP
Figure 4
). For example, if a macrocell requires 14 product
shows how parallel expanders can be
PEXP
.
Altera Corporation