V3020

`Supply current typically 390 nA at 3 V
`50 ns access time with 50 pF load capacitance
`Fully operational from 1.2 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
`TSSO8 and SO8 packages
`On request extended temperature range, -40 to +125
`Pin compatible with the V3021

The V3020 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) orDS 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 V3020 has no busy states and there is no danger of a clock update while accessing. Supply current is typically 390 nA at V = 3.0 V. Battery operation is supported by complete DD functionality down to 1.2 V. The oscillator s tability is typically 0.3 ppm/V.