R2023K datasheet(35/50 Pages) RICOH

35 / 50 page

R2023K/T

2. Access to R2023K/T at random, or synchronized with external clock that has no relation to R2023K/T, or

synchronized with periodic interrupt in pulse mode.

3. Access to R2023K/T more than 2 times per each second on average.

For more details, please contact to Ricoh.

• How to evaluate the clock gain or loss

The oscillator adjustment circuit is configured to change time counts of 1 second on the basis of the settings of the

oscillation adjustment register once in 20 seconds or 60 seconds.

The oscillation adjustment circuit does not

effect the frequency of 32768Hz-clock pulse output from the 32KOUT pin.

Therefore, after writing the oscillation

adjustment register, we cannot measure the clock error with probing 32KOUT clock pulses. The way to measure

the clock error as follows:

(1) Output a 1Hz clock pulse of Pulse Mode with interrupt pin

Set (0,0,x,x,0,0,1,1) to Control Register 1 at address Eh.

(2) After setting the oscillation adjustment register, 1Hz clock period changes every 20seconds ( or every 60

seconds) like next page figure.

1Hz clock pulse

1 time

19 times

Measure the interval of T0 and T1 with frequency counter.

A frequency counter with 7 or more digits is

recommended for the measurement.

(3) Calculate the typical period from T0 and T1

T = (19

×T0+1×T1)/20

Calculate the time error from T.

R2023K Datasheet(PDF) 35 Page - RICOH electronics devices division