R2061L01-E2 Datasheet, PDF(37/60 Page) RICOH electronics devices division – 3 Wire Interface Real-Time Clock ICs with Battery Backup Switch-Over Function

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R2061L01-E2 Datasheet, PDF (37/60 Pages) RICOH electronics devices division – 3 Wire Interface Real-Time Clock ICs with Battery Backup Switch-Over Function

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* R2061K (FFP12) is the discontinued product as of July, 2016.

R2061x

NO.EA-112-160701

(3) When Oscillation Frequency Is Lower Than Target Frequency (Causing Time Count Loss)

When DEV=0:

Oscillation adjustment value = (Oscillation frequency - Target Frequency)

Oscillation frequency ï´ 3.051 ï´ 10-6

ï» (Oscillation Frequency â Target Frequency) ï´ 10

When DEV=1:

Oscillation adjustment value = (Oscillation frequency - Target Frequency)

Oscillation frequency ï´ 1.017 ï´ 10-6

ï» (Oscillation Frequency â Target Frequency) ï´ 30

Oscillation adjustment value calculations are exemplified below

(A) For an oscillation frequency = 32768.85Hz and a target frequency = 32768.05Hz

When setting DEV bit to 0:

Oscillation adjustment value = (32768.85 - 32768.05 + 0.1) / (32768.85 ï´ 3.051 ï´ 10-6)

ï» (32768.85 - 32768.05) ï´ 10 + 1

= 9.001 ï» 9

In this instance, write the settings (DEV,F6,F5,F4,F3,F2,F1,F0)=(0,0,0,0,1,0,0,1) in the oscillation adjustment

distance from 01h.

When setting DEV bit to 1:

Oscillation adjustment value = (32768.85 - 32768.05 + 0.0333) / (32768.85 ï´ 1.017 ï´ 10-6)

ï» (32768.85 - 32768.05) ï´ 30 + 1

= 25.00 ï» 25

In this instance, write the settings (DEV,F6,F5,F4,F3,F2,F1,F0)=(1,0,0,1,1,0,0,1) in the oscillation adjustment

(B) For an oscillation frequency = 32762.22Hz and a target frequency = 32768.05Hz

When setting DEV bit to 0:

Oscillation adjustment value = (32762.22 - 32768.05) / (32762.22 ï´ 3.051 ï´ 10-6)

ï» (32762.22 - 32768.05) ï´ 10

= -58.325 ï» -58

To represent an oscillation adjustment value of - 58 in 7-bit coded decimal notation, subtract 58 (3Ah) from 128

(80h) to obtain 46h. In this instance, write the settings of (DEV,F6,F5,F4,F3,F2,F1,F0) = (0,1,0,0,0,1,1,0) in the

oscillation adjustment register. Thus, an appropriate oscillation adjustment value in the presence of any time

count loss represents a distance from 80h.

When setting DEV bit to 1:

Oscillation adjustment value = (32762.22 - 32768.05) / (32762.22 ï´ 1.017 ï´ 10-6)

ï» (32762.22 - 32768.05) ï´ 30

= -174.97 ï» -175

Oscillation adjustment value can be set from -62 to 63. Then, in this case, Oscillation adjustment value is out of

range.

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