Page 814 of 906 NTDK20 Small System Controller card553-3001-211 Standard 3.00 August 2005MemoryThe majority of system and customer configured data is both controlled andstored on the NTDK20 SSC card’s Flash ROM. An active and backup copyof customer data is also kept on the Flash ROM.In the event of data loss, the NTDK20 SSC card also retains a copy ofcustomer files in an area called the Backup flash drive. The NTDK20 SSCcard is equipped with 8MB of temporary memory space called DRAM.DRAM functions much like RAM on a computer system. It stores andprocesses temporary automated routines and user-programmed commandswhile the system is running. The DRAM on the SSC card stores operatingsystem files, user files, overlay data, patch codes, and the active copy of thecustomer database.The NTDK20 SSC card’s Flash daughterboard is the NTTK25. It performsmost of the system software storage and data processing.NTTK25 daughterboardThe NTTK25 is a 48 MB daughterboard comprised of Flash ROM andPrimary Flash drive. It is required in the Call Server and MG 1000S.The Flash ROM holds 32 MB of ROM memory, comprising operating systemdata and overlay programs. Flash ROM is expandable using an expansionflash daughterboard.The Primary Flash drive contains 16 MB of storage space. Most of the datastorage is allocated to the Primary Flash drive – the main storage area ofcustomer configured data.Other system data such as the Secure Storage Area (SSA) also resides in theFlash drive. The SSA holds data that must survive power interruptions.The Boot ROM is a 2 MB storage device located on the NTDK20 SSC card.The Boot ROM contains the boot code, system data, patch data, and thebackup copy of the Primary Flash drive’s customer database.
