R
XC3000 Series Field Programmable Gate Arrays
XC3100L CLB Switching Characteristics Guidelines
Testing of the switching parameters is modeled after testing methods specified by MIL-M-38510/605. All devices are 100%
functionally tested. Since many internal timing parameters cannot be measured directly, they are derived from benchmark
timing patterns. The following guidelines reflect worst-case values over the recommended operating conditions. For more
detailed, more precise, and more up-to-date timing information, use the values provided by the timing calculator and used
in the simulator.
Speed Grade
Symbol
-3
-2
Description
Min
Max
Min
Max
Units
Combinatorial Delay
Logic Variables A, B, C, D, E, to outputs X or Y
Sequential delay
1
8
T
2.7
2.2
ns
ILO
Clock k to outputs X or Y
Clock k to outputs X or Y when Q is returned
through function generators F or G to drive X or Y
T
T
2.1
4.3
1.7
3.5
ns
ns
CKO
QLO
Set-up time before clock K
Logic Variables
Data In
Enable Clock
Reset Direct Inactive
A, B, C, D, E
DI
EC
RD
2
4
6
T
2.1
1.4
2.7
1.0
1.8
1.3
2.5
1.0
ns
ns
ns
ns
ICK
T
DICK
T
ECCK
Hold Time after clock K
Logic Variables
Data In
A, B, C, D, E
DI
EC
3
5
7
T
0
0.9
0.7
0
0.9
0.7
ns
ns
ns
CKI
T
CKDI
T
CKEC
Enable Clock
Clock
7
Clock High time
Clock Low time
Max. flip-flop toggle rate
11
12
T
T
1.6
1.6
270
1.3
1.3
325
ns
ns
MHz
CH
CL
F
CLK
Reset Direct (RD)
RD width
13
9
T
T
2.7
2.3
ns
ns
RPW
delay from RD to outputs X or Y
3.1
2.7
RIO
Global Reset (RESET Pad)
RESET width (Low)
ns
ns
(XC3142L)
delay from RESET pad to outputs X or Y
T
T
12.0
12.0
MRW
12.0
12.0
MRQ
Advance
Notes: 1. The CLB K to Q delay (T
, #8) of any CLB, plus the shortest possible interconnect delay, is always longer than the Data
, #5) of any CLB on the same die.
CKO
In hold time requirement (T
CKDI
2. T , T
and T
are specified for 4-input functions. For 5-input functions or base FGM functions, each of these
ILO QLO
ICK
specifications for the XC3100L family increase by 0.35 ns (-3) and 0.29 ns (-2).
November 9, 1998 (Version 3.1)
7-61
XILINX [ XILINX, INC ]
