MAX 5000 Programmable Logic Device Family Data Sheet
Figure 3. Expander Product Terms
To Macrocell Array
8 or 20
Dedicated
Inputs
24 Programmable
Interconnect Signals
(Multi-LAB Devices Only)
32 or 64
Expander
Product Terms
Macrocell
Feedbacks
Expanders are fed by all signals in the LAB. One expander can feed all
macrocells in the LAB or multiple product terms in the same macrocell.
Because expanders also feed the secondary product terms of each
macrocell, complex logic functions can be implemented without using
additional macrocells. A small delay (tSEXP) is incurred when shared
expanders are used.
Programmable Interconnect Array
The multi-LAB MAX 5000 devices—EPM5064, EPM5128, EPM5130, and
EPM5192 devices—use a PIA to route signals between the various LABs.
The PIA, which is fed by all macrocell and I/O pin feedbacks, routes only
the signals required for implementing logic in an LAB. While the routing
delays of segmented routing schemes in masked or field-programmable
gate arrays (FPGAs) are cumulative, variable, and path-dependent, the
MAX 5000 PIA has a fixed delay. The PIA thus eliminates skew between
signals and makes timing performance easy to predict.
I/O Control Blocks
Each LAB has an I/O control block that allows each I/O pin to be
individually configured for input, output, or bidirectional operation (see
Figure 4). The I/O control block is fed by the macrocell array. A dedicated
macrocell product term controls a tri-state buffer, which drives the I/O
pin.
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Altera Corporation
ALTERA [ ALTERA CORPORATION ]
