AR# 5688

LogiCORE PCI - In my target application, STOP_IO is asserted, S_TERM is low, and S_READY is High

Description

General Description:

Table 6-1 "Data Phase Control Signals for Targets" in the PCI32 User's Guide describes 4 conditions for a target application based upon the values of S_TERM and S_READY. The second condition, "Normal", states that STOP_IO is value logic high in this condition.

It is possible that STOP_IO may actually be logic Low, despite S_TERM being Low and S_READY being High.

Solution

In a circumstance where an invalid address location (i.e., one that does not end in a 0, 4, 8, or C) is supplied to the target, the target may assert STOP_IO to indicate an invalid attempt at a transaction.

This is one of various possible conditions that might cause STOP_IO to be asserted.

AR# 5688
Date 12/15/2012
Status Active
Type General Article