What is the difference between the Ready/Busy (RY/BY#) output pin status and the Data Polling (DQ7) method?
The RY/BY# output pin only monitors the current status of the device, and cannot determine if an operation has completed successfully. Since the RY/BY# is an open-drain output pin, it will require the installation of a (4.7K to 10K) pull-up resistor to successfully use this pin. RY/BY# cannot be monitored/accessed via command definitions. The RY/BY# can be left floating if it is not used. The data polling (DQ7) method does not require any conditioning, and will determine if an operation has completed successfully. You may initiate a status read after executing a program or erase command sequence.