RX8111CE
Page
−
2
ETM61E-01
Low Power Real-time Clock Module with I
2
C Interface and Time Stamp Function
RX8111CE
•
Built-in frequency adjusted 32.768 kHz crystal unit
•
Interface Type : I
2
C (up to 400 kHz)
•
Low current consumption at backup
: 100 nA / 3.0 V Typ.
•
Wide operating voltage range : 1.6
V
to
5.5
V
•
Wide time-keeper voltage range : 1.1
V
to
5.5
V
•
Auto power switching function : Automatically switches to backup power supply
by monitoring the V
DD
voltage.
•
Time stamp function : 8times time-stamp,1/256 seconds with many selectable trigger.
•
Time stamp memory can be used as users memory; 512 bit, 64 word
8 bit
•
Alarm interruption : Day, date, hour, minute, second
•
The various functions include full calendar, seconds alarm, wakeup timer, and 32.768 kHz output
•
Self monitoring function : Voltage detection, Crystal oscillation stop, etc.
The I
2
C-Bus is a trademark of NXP Semiconductors.
1. Overview
RX8111CE is a real-time clock module with integrated 32.768 kHz crystal oscillator and I
2
C interface. In addition to
providing a calendar (year, month, date, day, hour, minute, second), this module provides other functions including time-
stamp from 1/1024 second to year, alarm, wakeup timer, time update interruption, and 32.768 kHz output. Time stamp
function can record maximum of 8 events. Using the backup battery charge control function and the interface power supply
input pin, RX8111CE can support various power supply circuits. All of the functions mentioned above are offered in a thin
and compact 3.2 x 2.5 ceramic package which could be used in various applications requiring small footprints.
2. Block Diagram
V
OUT
FOUT
V
BAT
GND
Bus
Interface
Register
Control
(System
Control)
RTC Main Circuit
32kHz
to
1kHz
Divider
512Hz
to
1Hz
Divider
Clock
and
Calendar
SDA
SCL
V
DD
V
IO
Power
Control
(V
DET
)
（
V
CMP
）
V
DD
Detector
OSC
32.768kHz
Timer
Register
Interrupts
Controller
/INT
User RAM
Event
Controller
EVIN
I/O
V
BAT
Detector
（
V
LOW
）
FOUT Controller
Alarm,Timer,
Update,Event
FOUT,
Timer
Figure 1 Block Diagram
