Real-Time Clock (RTC)
with internal 64 bit ROM

Pinout

        SOIC6-150mil
         +---\/---+
     GND | 1     6| X2
  1-WIRE | 2     5| X1
     Vdd | 3     4| Vbat
         +--------+

Frequency

SOIC6
Set reader to FREQ, put black probe to GND, red probe to 5 and to 6 to measure CPU clock