XC3S50 Datasheet, PDF (57/192 Pages) Xilinx, Inc – Revolutionary 90-nanometer process technology

Spartan-3 FPGA Family: DC and Switching Characteristics
R
Switching Characteristics
All Spartan-3 devices are available in two speed grades: –4
and the higher performance –5. Switching characteristics in
this document may be designated as Advance, Preliminary,
or Production. Each category is defined as follows:
Advance: These specifications are based on simulations
only and are typically available soon after establishing
FPGA specifications. Although speed grades with this des-
ignation are considered relatively stable and conservative,
some under-reporting might still occur. All –5 grade num-
bers are engineering targets: characterization is still in
progress.
Preliminary: These specifications are based on complete
early silicon characterization. Devices and speed grades
with this designation are intended to give a better indication
of the expected performance of production silicon. The
probability of under-reporting preliminary delays is greatly
reduced compared to Advance data.
Production: These specifications are approved once
enough production silicon of a particular device family mem-
ber has been characterized to provide full correlation
between speed files and devices over numerous production
lots. There is no under-reporting of delays, and customers
receive formal notification of any subsequent changes. Typ-
ically, the slowest speed grades transition to Production
before faster speed grades.
All specified limits are representative of worst-case supply
voltage and junction temperature conditions. Unless other-
wise noted, the following applies: Parameter values apply to
all Spartan-3 devices. All parameters representing voltages
are measured with respect to GND.
Timing parameters and their representative values are
selected for inclusion below either because they are impor-
tant as general design requirements or they indicate funda-
mental device performance characteristics. The Spartan-3
speed files (V1.29), part of the Xilinx Development Soft-
ware, are the original source for many but not all of the val-
ues. For more complete, more precise, and worst-case
data, use the values reported by the Xilinx static timing ana-
lyzer (TRACE in the Xilinx development software) and
back-annotated to the simulation netlist.
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Advance Product Specification