DS1207 Datasheet | Dallas Semiconductor

FEATURES PIN ASSIGNMENT - Cannot be deciphered by reverse engineering - Time allotment from one day to 512 days for trial periods, rentals, and leasing DALLAS DS1207 Time Key - Partitioned memory thwarts pirating - User-insertable possession packaging allows personal - Exclusive blank keys on request - Appropriate identification can be made with a 64-bit reprogrammable memory SIDE - Unreadable 64-bit match code virtually prevents discovery by exhaustive search with over 1019 possibilities obscures real accesses - Random data generation on incorrect match codes - 384 bits of secure read/write memory create additional barriers by permitting data changes as often as needed and secure read/write memory can occur if tampering is detected - Rapid erasure of identification, security match code - Durable and rugged - Applications include software authorization, gray market software protection, proprietary data, financial transactions, secure personnel areas, and system access control DESCRIPTION The DS1207 Time Key is a miniature security system that stores 64 bits of user-definable identification code and a 64-bit security match code that protects 384 bits of read/write nonvolatile memory. The 64-bit identification code and the security match code are programmed into the Time Key via a special program mode operation. After programming, the Time Key follows a procedure with a serial format to retrieve or update data. The Time Key is set to expire from one day to 512 days or infinity, as w w t a .D w S a e h NC RST DQ CLK GND BOTTOM: PIN VIEW 1.0 IN t e U 4 .c m o See Mech. Drawings Section PIN DESCRIPTION Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 No connection Reset Data input/output Clock Ground specified by the customer. The Time Key starts its countdown from the first access by the end user. Interface cost to a microprocessor is minimized by on-chip circuitry that permits data transfer with only three signals: Clock (CLK), Reset (RST) and Data Input/...