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Spartan-3A DSP FPGA Family: DC and Switching Characteristics
DS610 (v3.0) October 4, 2010
www.xilinx.com
Product Specification
28
Three-State Output Propagation Times
Table 24:
Timing for the IOB Three-State Path
Symbol
Description
Conditions
Device
Speed Grade
Units
-5
-4
Max
Max
Synchronous Output Enable/Disable Times
T
IOCKHZ
Time from the active transition at the OTCLK
input of the Three-state Flip-Flop (TFF) to when
the Output pin enters the high-impedance state
LVCMOS25, 12 mA
output drive, Fast slew
rate
All
1.13
1.39
ns
T
IOCKON
(2)
Time from the active transition at TFF’s OTCLK
input to when the Output pin drives valid data
All
3.08
3.35
ns
Asynchronous Output Enable/Disable Times
T
GTS
Time from asserting the Global Three State
(GTS) input on the STARTUP_SPARTAN3A
primitive to when the Output pin enters the
high-impedance state
LVCMOS25, 12 mA
output drive, Fast slew
rate
All
9.47
10.36
ns
Set/Reset Times
T
IOSRHZ
Time from asserting TFF’s SR input to when the
Output pin enters a high-impedance state
LVCMOS25, 12 mA
output drive, Fast slew
rate
All
1.61
1.86
ns
T
IOSRON
(2)
Time from asserting TFF’s SR input at TFF to
when the Output pin drives valid data
All
3.57
3.82
ns
Notes:
1.
The numbers in this table are tested using the methodology presented in
Table 26
and are based on the operating conditions set forth in
Table 7
and
Table 10
.
2.
This time requires adjustment whenever a signal standard other than LVCMOS25 with 12 mA drive and Fast slew rate is assigned to the
data Output. When this is true,
add
the appropriate Output adjustment from
Table 25
.