
DS1390–DS1394
Low-Voltage SPI/3-Wire RTCs with
Trickle Charger
5
Maxim Integrated
CS
CPHA = 1
SCLK
tCC
tDC
tR
tF
tCCH
tCWH
tCDH
tCL
tCH
DIN
W/R
A6
A0
D0
WRITE ADDRESS BYTE
NOTE: SCLK CAN BE EITHER POLARITY SHOWN FOR CPOL = 1.
DOUT
D7
READ DATA BYTE
HIGH IMPEDANCE
Figure 2a. Timing Diagram—SPI Write Transfer (Mode 3)
CS
CPHA = 0
SCLK
tCC
tDC
tR
tF
tCCH
tCWH
tCDH
tCL
tCH
DIN
W/R
A6
A0
D0
WRITE ADDRESS BYTE
NOTE: SCLK CAN BE EITHER POLARITY SHOWN FOR CPOL = 0.
DOUT
D7
READ DATA BYTE
HIGH IMPEDANCE
Figure 2b. Timing Diagram—SPI Write Transfer (Mode 0)