DS28DG02 Datasheet | Dallas Semiconductor

DESCRIPTION The DS28DG02 bines 2Kb (256 x 8) EEPROM with 12 PIO lines, a real-time clock (RTC) and calendar with alarm function, a CPU reset monitor, a battery monitor, and a watchdog. munication with the device is acplished with an industrystandard SPI™ interface. The user EEPROM is organized as four blocks of 64 bytes each with single-byte and up to 16-byte page write capability. Additional registers provide access to PIOs and to setup functions. Individual PIO lines can be configured as inputs or outputs. The power-on state of PIOs programmed as outputs is stored in nonvolatile (NV) memory. All PIOs may be reconfigured by the user through the serial interface. The RTC/calendar operates in the 12/24-hour format and automatically corrects for leap years. Battery monitor threshold and watchdog timeout are userprogrammable through NV registers. The reset monitor generates a reset to the CPU if the voltage at the VCC pin falls below the factory-set limit. The reset output includes a debounce circuit for manual pushbutton reset. APPLICATIONS Asset-Tracking Systems Broadband Access Network Equipment Patient-Monitoring Systems Home Lighting Control Systems Holter Heart Monitors Typical Operating Circuit appears on page 32. Pin Configuration appears on page 33. FEATURES - 2Kb (256 x 8) EEPROM Organized in Four 64-Byte Blocks - Single Byte and Up to 16-Byte EEPROM Write Sequences - EEPROM Write-Protect Control Pin Protects 1, 2, or All 4 Blocks - Endurance 200k Cycles per Page at +25°C; 10ms (max) EEPROM Write Cycle - SPI Serial Interface Supporting Modes (0,0) and (1,1) at Up to 2MHz Clock Frequency - 12 PIO Lines with LED Drive Capability - Each PIO is Configured to Input or Output, Open-Drain/Push-Pull on Startup by Stored Value - All PIOs are Reconfigurable After Startup - RTC/Calendar/Alarm with BCD Format and Leap-Year pensation - RTC Controlled Through 32.768k Hz, 12.5p F Crystal or External TCXO - CPU Reset Through Fast-Response Precision VCC Monitor with...