DeepCover Security Manager with 64B Nonimprinting, Battery-Backed Encryption Key SRAM

The DS3600 is a secure supervisor with 64 bytes of SRAM for applications requiring the secure storage of encryption keys, including POS terminals. The 64B key memory is constantly complemented in the background to prevent oxide stress and memory imprinting. In the event of a qualified tamper event, the key memory is rapidly cleared and a negative bias is applied to clear SRAM external to the DS3600.

The device includes a real-time clock (RTC), CPU supervisor, watchdog timer, and on-chip temperature sensor. In the event of a primary power failure, an external battery source is automatically switched in to keep the key memory, RTC, and tamper detection circuitry active. The DS3600 provides low-leakage tamper-detection inputs for interface to external sensors, interlocks, and anti-tamper meshes. The DS3600 will also invoke a tamper event if the backup battery drops below a specified threshold, absolute temperature or temperature rate-of-change exceeds programmed limits, or crystal oscillator frequency falls outside a specified window. The tamper event is latched and time stamped for future debugging purposes.

Access to the RTC, tamper monitoring, key memory, and device configuration is conducted through an 3-wire serial interface. The DS3600 is assembled in a Pb-free CSBGA package, which enhances key security in that the leads are not exposed to the outer edges of the package.

Applications

* Alarm Systems * Gaming * IT Security * Point-of-Sale Terminals * Routers/Switches * Secure Software-Defined Radios (SDRs)

* 64-Byte Nonimprinting Key Memory with High-Speed Erase

* External SRAM Clear upon Qualified Tamper Event

* RTC with Leap Year Compensation Valid Up to 2100

* Watchdog Timer

* CPU Supervisor

* Four General-Purpose, Tamper-Detect Comparators with Associated Reference

* Tamper-Detect Logic Input

* Service and Case Switch Logic Inputs

* On-Chip Temperature Sensing with Rate-of-Change Detector

* On-Chip Random-Number Generator

* Latching and Time Stamping of Tamper Events

* XTAL Oscillator Tamper Monitoring

* Low Power Consumption

* 3-Wire Serial Interface

* BGA Package with No Horizontally Exposed Leads