EPM3256A ALTERA [Altera Corporation], EPM3256A Datasheet - Page 8

• Manufacturer Part Number: EPM3256A
• Description: Programmable Logic Device Family
• Manufacturer: ALTERA [Altera Corporation]

MAX 3000A Programmable Logic Device Family Data Sheet
8
Shareable Expanders
Each LAB has 16 shareable expanders that can be viewed as a pool of
uncommitted single product terms (one from each macrocell) with
inverted outputs that feed back into the logic array. Each shareable
expander can be used and shared by any or all macrocells in the LAB to
build complex logic functions. Shareable expanders incur a small delay
(t
macrocells.
Figure 3. MAX 3000A Shareable Expanders
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.
SEXP
Shareable expanders can be shared by any or all macrocells in an LAB.
).
36 Signals
from PIA
Figure 3
shows how shareable expanders can feed multiple
Expanders
16 Shared
Product-Term Select Matrix
Altera Corporation
Macrocell
Product-Term
Logic
Macrocell
Product-Term
Logic