Answers Database

PCI macro: Target state machine goes into an invalid state after reset.


Record #1488

Product Family:  Software

Product Line:  Logicore

Problem Title:
PCI macro: Target state machine goes into an invalid state after reset.


Problem Description:
In the version 1.0 PCI macro, after asserting RST-, the
Target State Machine (TSM) may appear to be in a "none-hot" state.
This is because the signal FRAME- (the registered version of
FRAME) is low, and the idle section of the TSM is clocked low
while none of the other states go high. This is due to the schematic
W-IF-OFZ having an IFD Flip flop instead of an IFDI. When the reset
occurs, the IFD clears and puts the wrong signal on FRAME-.


Solution 1:

To solve this, replace the IFD with an IFDI. Version 1.1
already has this change.



End of Record #1488