Military ProASIC3/EL Device Family Overview
The inputs of the six CCC blocks are accessible from the FPGA core or from one of several inputs
located near the CCC that have dedicated connections to the CCC block.
The CCC block has these key features:
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Wide input frequency range (f
IN_CCC
) = 1.5 MHz up to 250 MHz
Output frequency range (f
OUT_CCC
) = 0.75 MHz up to 250 MHz
2 programmable delay types for clock skew minimization
Clock frequency synthesis
Internal phase shift = 0°, 90°, 180°, and 270°. Output phase shift depends on the output
divider configuration.
Output duty cycle = 50% ± 1.5% or better
Low output jitter: worst case < 2.5% × clock period peak-to-peak period jitter when single
global network used
Maximum acquisition time is 300 µs
Exceptional tolerance to input period jitter—allowable input jitter is up to 1.5 ns
Four precise phases; maximum misalignment between adjacent phases of 40 ps × 250 MHz /
f
OUT_CCC
Additional CCC specifications:
Global Clocking
Military ProASIC3/EL devices have extensive support for multiple clocking domains. In addition to
the CCC and PLL support described above, there is a comprehensive global clock distribution
network.
Each VersaTile input and output port has access to nine VersaNets: six chip (main) and three
quadrant global networks. The VersaNets can be driven by the CCC or directly accessed from the
core via multiplexers (MUXes). The VersaNets can be used to distribute low-skew clock signals or for
rapid distribution of high-fanout nets.
I/Os with Advanced I/O Standards
The military ProASIC3/EL family of FPGAs features a flexible I/O structure, supporting a range of
voltages (1.5 V, 1.8 V, 2.5 V, and 3.3 V). In addition, 1.2 V I/O operation is supported for military
ProASIC3EL devices. Military ProASIC3/EL FPGAs support different I/O standards, including single-
ended, differential, and voltage-referenced (military ProASIC3EL). The I/Os are organized into
banks, with two, four, or eight (military ProASIC3EL only) banks per device. The configuration of
these banks determines the I/O standards supported. For military ProASIC3EL, each I/O bank is
subdivided into V
REF
minibanks, which are used by voltage-referenced I/Os. V
REF
minibanks contain
8 to 18 I/Os. All the I/Os in a given minibank share a common V
REF
line. Therefore, if any I/O in a
given V
REF
minibank is configured as a V
REF
pin, the remaining I/Os in that minibank will be able to
use that reference voltage.
Each I/O module contains several input, output, and enable registers. These registers allow the
implementation of the following:
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Single-data-rate applications (e.g., PCI 66 MHz, bidirectional SSTL 2 and 3, Class I and II)
Double-data-Rate applications (e.g., DDR LVDS, B-LVDS, and M-LVDS I/Os for point-to-point
communications, and DDR 200 MHz SRAM using bidirectional HSTL Class II).
Military ProASIC3EL banks support LVPECL, LVDS, B-LVDS, and M-LVDS. B-LVDS and M-LVDS can
support up to 20 loads.
Part Number and Revision Date
Part Number 51700106-001-0
Revised August 2008
v1.0
1-7
ACTEL [ Actel Corporation ]
