R
XC4000E and XC4000X Series Field Programmable Gate Arrays
XC4000E/EX/XL Program Readback Switching Characteristic Guidelines
Testing of the switching parameters is modeled after testing methods specified by MIL-M-38510/605. All devices are 100%
functionally tested. Internal timing parameters are not measured directly. They are derived from benchmark timing patterns
that are taken at device introduction, prior to any process improvements.
The following guidelines reflect worst-case values over the recommended operating conditions.
Finished
Internal Net
rdbk.TRIG
T
RCRT
T
RCRT
2
T
RTRC
T
RTRC
2
1
1
rdclk.I
5
6
T
RCL
T
RCH
4
rdbk.RIP
T
RCRR
DUMMY
DUMMY
VALID
VALID
rdbk.DATA
T
RCRD
7
X1790
6
E/EX
Description
Symbol
Min
Max
Units
rdbk.TRIG
rdclk.1
rdbk.TRIG setup to initiate and abort Readback
rdbk.TRIG hold to initiate and abort Readback
1
2
TRTRC
TRCRT
200
50
-
-
ns
ns
rdbk.DATA delay
rdbk.RIP delay
High time
7
6
5
4
TRCRD
TRCRR
TRCH
-
-
250
250
500
500
ns
ns
ns
ns
250
250
Low time
TRCL
Note 1:
Note 2:
Timing parameters apply to all speed grades.
If rdbk.TRIG is High prior to Finished, Finished will trigger the first Readback.
XL
Description
Symbol
Min
Max
Units
rdbk.TRIG
rdclk.1
rdbk.TRIG setup to initiate and abort Readback
rdbk.TRIG hold to initiate and abort Readback
1
2
TRTRC
TRCRT
200
50
-
-
ns
ns
rdbk.DATA delay
rdbk.RIP delay
High time
7
6
5
4
TRCRD
TRCRR
TRCH
-
-
250
250
500
500
ns
ns
ns
ns
250
250
Low time
TRCL
Note 1:
Note 2:
Timing parameters apply to all speed grades.
If rdbk.TRIG is High prior to Finished, Finished will trigger the first Readback.
May 14, 1999 (Version 1.6)
6-57
XILINX [ XILINX, INC ]
