RS5C372A-E2-F Datasheet, PDF (16/57 Pages) RICOH electronics devices division – I2C bus SERIAL INTERFACE REAL-TIME CLOCK IC

RS5C372A/B
5. Oscillation halt sensing
The oscillation halt sensing function uses a register to store oscillation halt information. This function may be
used to determine if the RS5C372A/B supply power has been booted from 0V and if it has been backed up.
This function is useful for determining if clock data is valid or invalid.
6. Periodic interrupt
 RS5C372A
The RS5C372A can output periodic interrupt pulses in addition to alarm function from the INTRA and INTRB
pins.
This frequency may be selected from 2Hz (every 0.5 seconds), 1Hz (every second), 1/60Hz (every minute),
1/3600Hz (every hour) and monthly (1st of month).
Output wave form for periodic interrupt may be selected from regular pulse waveform (2Hz and 1Hz) and
waveforms (every second, every minute, every hour and every month) that are appropriate for CPU level
interrupt. Outputs may be selected either INTRA or INTRB . The RS5C372A has polling function that monitors
pin status in the register.
 RS5C372B
The RS5C372B can output periodic interrupt pulses in addition to alarm function from the INTR pin. This
frequency may be selected from 2Hz (every 0.5 seconds), 1Hz (every second), 1/60Hz (every minute), 1/3600Hz
(every hour) and monthly (1st of month).
Output wave form for periodic interrupt may be selected from regular pulse waveform (2Hz and 1Hz) and
waveforms (every second, every minute, every hour and every month) that are appropriate for CPU level
interrupt. Periodic Interrupt outputs from INTR . The RS5C372B has polling function that monitors pin status in
the register.
7. 32-kHz clock output
 RS5C372A
The RS5C372A may output oscillation frequency from the INTRB pin. This clock output is set for output by default,
which is set to on or off by setting the register.
 RS5C372B
The RS5C372B may output oscillation frequency from the 32KOUT pin. This clock output is set for output by
default, which is set to on or off by setting the register. The 32KOUT pin is CMOS push-pull output terminal.
Note
The year-digit counter of RS5C372A/B counts only lower two digits of a year and no counter is supplied for
upper two digits. When you are going to use this product in a system that must cope with “2000 year
problem” which shall be corrected by software.
15