Spartan-3E FPGA Family: DC and Switching Characteristics
DS312 (v4.1) July 19, 2013
Product Specification
137
Clock Buffer/Multiplexer Switching Characteristics
Table 99: CLB Distributed RAM Switching Characteristics
Symbol
Description
-5
-4
Units
Min
Max
Min
Max
Clock-to-Output Times
TSHCKO
Time from the active edge at the CLK input to data appearing on
the distributed RAM output
-2.05
-2.35
ns
Setup Times
TDS
Setup time of data at the BX or BY input before the active
transition at the CLK input of the distributed RAM
0.40
-0.46
-ns
TAS
Setup time of the F/G address inputs before the active transition
at the CLK input of the distributed RAM
0.46
-0.52
-ns
TWS
Setup time of the write enable input before the active transition at
the CLK input of the distributed RAM
0.34
-0.40
-ns
Hold Times
TDH
Hold time of the BX, BY data inputs after the active transition at
the CLK input of the distributed RAM
0.13
-0.15
-ns
TAH, TWH
Hold time of the F/G address inputs or the write enable input after
the active transition at the CLK input of the distributed RAM
0
-0
-ns
Clock Pulse Width
TWPH, TWPL
Minimum High or Low pulse width at CLK input
0.88
-1.01
-ns
Table 100: CLB Shift Register Switching Characteristics
Symbol
Description
-5
-4
Units
Min
Max
Min
Max
Clock-to-Output Times
TREG
Time from the active edge at the CLK input to data appearing on
the shift register output
-3.62
-4.16
ns
Setup Times
TSRLDS
Setup time of data at the BX or BY input before the active
transition at the CLK input of the shift register
0.41
-0.46
-ns
Hold Times
TSRLDH
Hold time of the BX or BY data input after the active transition at
the CLK input of the shift register
0.14
-0.16
-ns
Clock Pulse Width
TWPH, TWPL
Minimum High or Low pulse width at CLK input
0.88
-1.01
-ns
Table 101: Clock Distribution Switching Characteristics
Description
Symbol
Maximum
Units
Speed Grade
-5
-4
Global clock buffer (BUFG, BUFGMUX, BUFGCE) I input to O-output delay
TGIO
1.46
ns
Global clock multiplexer (BUFGMUX) select S-input setup to I0 and I1 inputs. Same
as BUFGCE enable CE-input
TGSI
0.55
0.63
ns
Frequency of signals distributed on global buffers (all sides)
FBUFG
333
311
MHz