Answers Database
FPGA Configuration: SyncToDone must apply to all devices in Daisy-Chain.
Record #4773
Product Family: Software
Product Line: M1 Graphical/General
Product Part: Design Manager
Product Version: 1.5
Problem Title:
FPGA Configuration: SyncToDone must apply to all devices in Daisy-Chain.
Problem Description:
URGENCY: Standard
GENERAL DESCRIPTION:
When Daisy-Chaining multiple FPGAs together for configuration,
if SynToDone was chosen in the Configuration Options for the
Master Mode device, but the Slaves are not specified as
SyncToDone, the Slave devices will not complete STARTUP and
become active.
Solution 1:
Re-run the configuration step in the S/W (BitGen) either
specifying SyncToDone for all devices in the Daisy-Chain, or
removing this option entirely.
Solution 2:
For Express Mode Daisy Chain configuration SyncToDone must be
specified on all devices so configuration is not disrupted.
When configuring in Express Mode (XC5200, XC4000XLA, SpartanXL
only), the FPGA enters the STARTUP sequence as soon as it's own
configuration memory is full because it does not use a
LengthCount as in the other modes. If one device in the chain
becomes active before others are done with configuration then
the activation of the IOs can interfere with the DATA bus.
End of Record #4773 - Last Modified: 11/20/98 10:21 |
