The security features of IS23SC1604 provide high levels of memory security protection for smart card applications. The memory is partitioned into four application zones. Each individual application zone is protected by multiple security codes from unauthorized read/write/erase access to the zone. In addition, an internal security fuse is available for the card issuer to fully personalize the device before releasing it to customer. The device also features an internal high-voltage charge pump for memory programming, 1,000,000 write/erase cycles and ten years of data retention.