SERIAL 4-WIRE
RX- 4581NB
DC characteristic Timing operation Initial setting
Processing terminals Setting register Time and calendar
Access operation (READ/WRITE) Timer interrupting function Others
　
DC characteristic
Consumption current
Q Is the maximum consumption current 0.8 A, even when there is an output to the AIRQ terminal while in the backup state?
A According to the specification, the maximum consumption current is 0.8 A when there is no output.
　
Timing operation
Timing malfunction
Q Time data is not renewed upon retrieval of clock data and the same time is always indicated, resulting in the data not being counted up from the start time. What are the potential causes?
A The internal quartz resonator may not be oscillating.

Potential causes are as follows:
-The metal end area (surrounded by a dotted circle) on the backside of a module is touching the substrate pattern, blocking the internal quartz resonator's oscillation.
-The internal quartz resonator is damaged due to a sudden impact such as being dropped.
The clock will not move if the internal quartz resonator does not oscillate, so the clock data being retrieved stays the same.
　
Initial setting
　
Processing terminals
Connecting the /ARQ and /TIRQ terminals
Q What are recommended values of pull up resisters connected to /AIRQ and /TIRQ ?
A These values vary depending on source voltages.

According to the condition regulated as the "L" output voltage of SDC electrical characteristics in the specification, IOL is 1mA. For example, when VDD is 3V, the value becomes 3V/1mA=3k.
In this case, the pull up resisters for /AIRQ and /TIRQ terminals must be more than 3k.
　
Setting register
　
Time and calendar
Calendar function
Q If time is set to 12:00:00 as a calendar and retrieved every second, count up is terminated at 12:00:02. Time is stuck at 12:00:02 thereafter. We are only using hours, minutes and seconds. Do any other registers need to be set?
A Normal operation cannot be performed if the control register at the "F" address and the extension register at the "D" address are not set.Furthermore, the STOP, RESET, and TEST bits must be set at the initial state.
　
Access operation (READ/WRITE)
　
Timer interrupting function
　
Others