SM8577B Datasheet, PDF (7/10 Pages) Nippon Precision Circuits Inc – Real-time Clock IC

Timing Diagrams
Data read
CE
CLK
DATA
Data write
tCES
tCLK
t t CLKH CLKL
tDATD
CE
CLK
DATA
tCES
tCLK
t t CLKH CLKL
tsD
tHD
SM8577B
tCE
t t f1
r1
tCE
t t r1
f1
FOUT output
FOUT
tr2
10%
tH
90%
tr2
t
Note that the 1 Hz and 32 kHz oscillators are not
synchronized to each other, so switching between 1
Hz and 32 kHz output temporarily shortens the duty
cycle. Accordingly, a wait time (≥ output frequency
period) should be incorporated when switching
during normal operation.
t _t CEH
RCV
tDZ
t t CEH RCV
50%
Duty=
tH
t
X
100(%)
NIPPON PRECISION CIRCUITS—7