ACEX 1K Programmable Logic Device Family Data Sheet
The logic array consists of logic array blocks (LABs). Each LAB contains
eight LEs and a local interconnect. An LE consists of a 4-input LUT, a
programmable flipflop, and dedicated signal paths for carry and cascade
functions. The eight LEs can be used to create medium-sized blocks of
logic—such as 8-bit counters, address decoders, or state machines—or
combined across LABs to create larger logic blocks. Each LAB represents
about 96 usable logic gates.
Signal interconnections within ACEX 1K devices (as well as to and from
device pins) are provided by the FastTrack Interconnect routing structure,
which is a series of fast, continuous row and column channels that run the
entire length and width of the device.
Each I/O pin is fed by an I/O element (IOE) located at the end of each row
and column of the FastTrack Interconnect routing structure. Each IOE
contains a bidirectional I/O buffer and a flipflop that can be used as either
an output or input register to feed input, output, or bidirectional signals.
When used with a dedicated clock pin, these registers provide exceptional
performance. As inputs, they provide setup times as low as 1.1 ns and
hold times of 0 ns. As outputs, these registers provide clock-to-output
times as low as 2.5 ns. IOEs provide a variety of features, such as JTAG
BST support, slew-rate control, tri-state buffers, and open-drain outputs.
Figure 1
shows a block diagram of the ACEX 1K device architecture. Each
group of LEs is combined into an LAB; groups of LABs are arranged into
rows and columns. Each row also contains a single EAB. The LABs and
EABs are interconnected by the FastTrack Interconnect routing structure.
IOEs are located at the end of each row and column of the FastTrack
Interconnect routing structure.
13
Tools
Altera Corporation
7
ETC [ ETC ]
