The Data Retention of CY7C343B-25HC devices is guaranteed to be 10 years under normal operating conditions. The retention of the data is independent of whether the device was in storage or was in use. In general we support the lifetime of all parts at 10 years. We use the Arrhenius model to calculate data retention. To qualify our parts for the 10-year lifetime, the CPLDs must pass High Temperature Operating Life (HTOL) tests before the part can be considered qualified. For data retention, we test the devices at 125 deg C for 1000 hours and/or 150 deg. C for 500 hours.
Please be noted our entire Cypress CPLD product are Obsolete and not recommended for new design and development. For more information on CPLD product, please visit our webpage: http://www.cypress.com/go/cpld