In order to complete the interface, there are two additional unique sequences to reset the device and to initiate a nonvolatile write cycle. A RESET condition is recognized by the X84041 whenever the system processor issues the following sequence:"read", "write a zero", and "read". This 3-bus cycle
sequence is used to initialize the part before a read or write sequence or to interrupt a sequence already in progress. An INITIATE NONVOLATILE WRITE
CYCLE condition is recognized by the X84041 whenever the system processor issues the following sequence: "read", "write a one", and "read". This
sequence is used to begin an internal write cycle after data has been loaded into the device. An additional feature of the device is the ability to determine the early completion of an internal nonvolatile write cycle.
This can be accomplished by "polling" the level of the I/O pin during a nonvolatile write cycle. When the I/O pin can be read as a logic HIGH, then the cycle is complete and the part is again able to interact within
the system.