Premature PCI cycle end

Question: What happens on a premature cycle end for the PCI-DP, e.g. by making SELECT inactive before the fourth DWORD?

 

Answer:

If SELECT is deactivated, the I/O's tristate and any values after SELECT is disabled will be ignored. SELECT drives the I/O state machine. SELECT should not deassert before RDY_IN, RDY_IN#, or RDY_OUT# goes active. This will impact our state machine.