RS5C313 RICOH Co.,Ltd., RS5C313 Datasheet - Page 24

• Manufacturer Part Number: RS5C313
• Description: Ultra-compact Real-time Clock Ic
• Manufacturer: RICOH Co.,Ltd.

24
RS5C313
11. Typical Software-based Operations
11.1 Initialization upon Power-on
11.2 Write Operation to Clock and Calendar Counters
YES
*
4
Interrupt cycle register←0h
Control register←0h, 4h
Set clock and calendar
counters and interrupt cycles.
Control register←3h, 7h
Control register←0h, 4h
Write to clock and
calendar counters.
Power-on
XSTP=0?
BSY=0?
BSY=0?
Start
CE=H
CE=L
No
YES
YES
*
6
*
*
*
*
NO
operations.
1
2
3
4
*
*
NO
operations.
1
2
Wait or
other
Wait or
CE=L
other
*
5
*
3
*
*
*
*
*
*
*
*
*
*
1) Switch the CE pin to the low level immediately after power-on.
2)
3) Turn off the INTR pin, whose output is uncertain at power-on.
4)
5) It takes 0.1-2 seconds to be set the BSY bit to 0 from oscillation starting upon
6) Set the XSTP bit to 0 by writing data to the control register.
1) After switching the CE pin to the high level, hold it at the high level until any
2) Write 0h for the 12-hour format or 4h for the 24-hour time display system.
3) The BSY bit is held at 1 for a maximum duration of 122.1 us.
4) Switch the CE pin to the low level to set the WTEN bit to 1.
Ensure stable oscillation by preventing the following:
1) Condensation on the crystal oscillator
2) Instantaneous disconnection of power
3) Generation of clock noises, etc. in the crystal oscillator
4) Charge of voltage exceeding prescribed maximum ratings
not be checked.
the ADJ bit to 1 for checking oscillaiton.
power-on from 0V. Provide an exit from an oscillation start loop to prepare
for oscillation failure.
0h for the 12-hour time display system.
4h for the 24-hour time display system.
When not making oscillation halt sensing (data validity), the XSTP bit need
Write to control register 3h for 12-hour format or 7h for 24-hour format. Set
subsequent operation requires switching it to the low level. (Note that
switching the CE pin to the low level sets the WTEN bit to 1.)
During write operation to the clock and calendar counters, one 1-second
digit carry causes a 1-second increment while two 1-second digit carries
also cause only a 1-second increment, which, in turn, causes a time delay.
to the individual pins of the IC
When using the XSTP bit