Revision 10
1-1
1 – eX FPGA Architecture and Characteristics
General Description
The eX family of FPGAs is a low-cost solution for low-power, high-performance designs. The inherent
low power attributes of the antifuse technology, coupled with an additional low static power mode, make
these devices ideal for power-sensitive applications. Fabricated with an advanced 0.22 mm CMOS
antifuse technology, these devices achieve high performance with no power penalty.
eX Family Architecture
Microsemi eX family is implemented on a high-voltage twin-well CMOS process using 0.22 m design
rules. The eX family architecture uses a “sea-of-modules” structure where the entire floor of the device is
covered with a grid of logic modules with virtually no chip area lost to interconnect elements or routing.
Interconnection among these logic modules is achieved using Microsemi patented metal-to-metal
programmable antifuse interconnect elements. The antifuse interconnect is made up of a combination of
amorphous silicon and dielectric material with barrier metals and has an "on" state resistance of 25
with
a capacitance of 1.0fF for low-signal impedance. The antifuses are normally open circuit and, when
programmed, form a permanent low-impedance connection. The eX family provides two types of logic
modules, the register cell (R-cell) and the combinatorial cell (C-cell).
The R-cell contains a flip-flop featuring asynchronous clear, asynchronous preset, and clock enable
(using the S0 and S1 lines) control signals (
Figure 1-1). The R-cell registers feature programmable clock
polarity selectable on a register-by-register basis. This provides additional flexibility while allowing
mapping of synthesized functions into the eX FPGA. The clock source for the R-cell can be chosen from
either the hard-wired clock or the routed clock.
Inclusion of the DB input and its associated inverter function enables the implementation of more than
4,000 combinatorial functions in the eX architecture in a single module.
Two C-cells can be combined together to create a flip-flop to imitate an R-cell via the use of the CC
macro. This is particularly useful when implementing non-timing-critical paths and when the design
engineer is running out of R-cells. More information about the CC macro can be found in the Maximizing Figure 1-1 R-Cell
DirectConnect
Input
CLKA,
CLKB,
Internal Logic
HCLK
CKS
CKP
CLR
PSET
Y
DQ
Routed
Data Input
S0
S1