We would like to know some more details about this issue.
1. Are you following the command sequence mentioned in the datasheet for reading data? Datasheet: http://www.cypress.com/file/215146/download , page 32.
2. Are you observing this issue in new devices? Or, did you program any data before reading data?
3. Please let us know the number of devices that you have tested and number of devices failed.
Thanks and Regards,
I got the solution for why the data is zero in parallel NOR FLash S29JL064J