MAX 3000A Programmable Logic Device Family Data Sheet
Figure 3. MAX 3000A Shareable Expanders
Shareable expanders can be shared by any or all macrocells in an LAB.
Macrocell
Product-Term
Logic
Product-Term Select Matrix
Macrocell
Product-Term
Logic
36 Signals
from PIA
16 Shared
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.
The MAX+PLUS II 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
PEXP
). For example, if a macrocell requires 14
product terms, the MAX+PLUS II 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
PEXP
.
8
Altera Corporation
ETC [ ETC ]
