MACH4-96-96-15 Lattice Semiconductor Corp., MACH4-96-96-15 Datasheet - Page 11

• Manufacturer Part Number: MACH4-96-96-15
• Description: High-performance Ee Cmos Programmable Logic
• Manufacturer: Lattice Semiconductor Corp.

The output switch matrix allows macrocells to be connected to any of several I/O cells within a
PAL block. This provides high flexibility in determining pinout, and allows design changes that will
not affect pinout.
In the MACH 4 devices, each PAL block has twice as many macrocells as I/O cells. The MACH 4
output switch matrix allows for half of the macrocells to drive I/O cells within a PAL block, in
combinations according to Figure 5. Each I/O cell can choose from eight macrocells; each
macrocell has a choice of four I/O cells.
The I/O Cell
The I/O cell (Figure 6) in the M4-96/96 consists of a three-state buffer and an input flip-flop. The
I/O cell is driven by one of the macrocells, as selected by the output switch matrix. Each I/O cell
can take its input from one of eight macrocells. The three-state buffer is controlled by an individual
product term. The direct I/O signal is available to the input switch matrix, and can be used
if desired.
Macro-
cell
a. Macrocell drives one of 3 I/Os
Figure 5.
Cell
cell
cell
cell
cell
cell
cell
I/O
cell
I/O
I/O
I/O
I/O
I/O
I/O
I/O
MACH4-96/96 Output Switch Matrix
MACH4-96/96-15
Macro-
Macro-
Macro-
Macro-
Macro-
Macro-
Macro-
Macro-
cell
cell
cell
cell
cell
cell
cell
cell
b. I/O can choose one of 8 macrocells
MUX
V A N T I S
Cell
I/O
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