V30218P

R EM MICROELECTRONIC-MARIN SA V3021 Ultra Low Power 1-Bit 32 kHz RTC Features n n n n n n n n n n n n n n Supply current typically 800 nA at 3 V 50 ns access time with 50 pF load capacitance Fully operational from 2.0 V to 5.5 V No busy states or danger of a clock update while accessing Serial communication on one line of a standard parallel data bus or over a conventional 3 wire serial interface Interface compatible with both Intel and Motorola Seconds, minutes, hours, day of month, month, year, week day and week number in BCD format Leap year and week number correction Time set lock mode to prevent unauthorized setting of the current time or date Oscillator stability 0.3 ppm / volt No external capacitor needed Frequency measurement and test modes Temperature range - 40 to +85 oC Packages DIP8 and SO8 Typical Operating Configuration WR or R/W RD or DS CPU Address Decoder ADDRESS BUS DATA BUS CS RD WR I/O XI XO V3021 Description The V3021 is a low power CMOS real time clock. Data is transmitted serially as 4 address bits and 8 data bits, over one line of a standard parallel data bus. The device is accessed by chip select (CS) with read and write control timing provided by either RD and WR pulse (Intel CPU) or DS with advanced R/W (Motorola CPU). Data can also be transmitted over a conventional 3 wire serial interface having CLK, data I/O and strobe. The V3021 has no busy states and there is no danger of a clock update while accessing. Supply current is typically ...