
Spartan-3 FPGA Family: DC and Switching Characteristics
DS099-3 (v1.5) December 17, 2004
Advance Product Specification
39
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11
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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 (v1.35), part of the Xilinx Development Software,
are the original source for many but not all of the values.
The speed grade designations for these files are shown in
Table 12
. 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.
Table 12:
Spartan-3 v1.35 Speed Grade Designations
Device
Advance
Preliminary
Production
XC3S50
–5
–4
XC3S200
–5
–4
XC3S400
–5
–4
XC3S1000
–5
–4
XC3S1500
–5
–4
XC3S2000
–4, –5
XC3S4000
–4, –5
XC3S5000
–4, –5