DS1305
Configuration 2: Backup Supply is a Rechargeable Battery or Super
Capacitor
Configuration 3: Battery Operate Mode
FUNCTION TABLE Table 3
MODE
Disable Reset
Write
CE
SCLK
Input Disabled
CPOL=1*
SDI
SDO
L
Input Disabled
Data Bit Latch
High Z
High Z
H
CPOL=0
CPOL=1
Read
H
X
Next data bit shift**
CPOL=0
* CPOL is the “Clock Polarity” bit that is set in the control register of the microcontroller.
** SDO remains at High Z until 8 bits of data are ready to be shifted out during a read.
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