Product Datasheet
IT8563
Real Time Clock
Features
Using external 32.768kHz quartz crystal
Supports I
2
C-Bus's high speed mode (400 kHz)
Includes time (Hour/Minute/Second) and calendar
(Year/Month/Date/Day) counter functions (BCD
code)
Description
The IT8563 serial real-time clock is a low-power
clock/calendar with a programmable square-wave output.
Address and data are transferred serially via a 2-wire
bidirectional bus. The clock/calendar provides seconds,
minutes, hours, day, date, month, and year information.
The date at the end of the month is automatically
adjusted for months with fewer than 31 days, including
corrections for leap year. The clock operates in the 24-
hour format indicator.
Table 1 shows the basic functions of IT8563. More
details are shown in section: overview of functions.
Programmable square wave output signal
Oscillator stop flag
Low backup current: typ. 400nA at V
DD
=3.0V and
T
A
=25
°
C
Operating range: 1.7V to 5.5V
Ordering Information
Part Number
IT8563WEX
IT8563UEX
IT8563TEX
Package
Lead free and Green 8-Pin SOIC
Lead free and Green 8-Pin MSOP
Lead free and Green 8-Pin TSSOP
X: Tape Reel
Note---E：Green Package,
Table 1.
Basic functions of IT8563
Item
1
Oscillator
Function
IT8563
-
-
1, 32, 1.024k, 32.768k
-
-
Source: Crystal: 32.768kHz
Oscillator enable/disable
Oscillator fail detect
Time display
2
Time
Century bit
Time count chain enable/disable
3
4
5
Interrupt
Communicat
ion
Control
Alarm interrupt
2-wire I
2
C bus
Burst mode
Write protection
6
External clock test mode
Power-on reset override
Programmable square wave output (Hz)
12-hour
24-hour
1
RayStar Microelectronics Technology Inc.
(Integration Technology Advanced Inc.)
Ver: 1.4
Product Datasheet
IT8563
Real Time Clock
Function Block
PT7C4363
X1
32.768
kHz
C
D
Comparator
Alarm Register
(Min, Hour, Day, Date)
OSC
Counter Chain
Time Counter
(Sec,Min,Hour,Day,Date,Month,Year)
X2
C
G
Control Register
Address
Decoder
Address
Register
I /O
Interface
(I
2
C)
Shift Register
SCL
INT
SQW
Alarm Interrupt Control
Square Wave Output Control
SDA
Note:
Built in C
D
=0, C
G
=23pF
2
RayStar Microelectronics Technology Inc.
(Integration Technology Advanced Inc.)
Ver: 1.4
Product Datasheet
IT8563
Real Time Clock
Pin Configuration
PT7C4363
1
X1
VCC
8
2
X2
INT
SQW
7
SCL
6
3
4
GND
SDA
5
DIP-8
SOIC-8
TSSOP-8
Pin Description
Pin no.
1
Pin
X1
Type
I
Description
Oscillator Circuit Input.
Together with X2, 32.768kHz crystal is connected between them.
2
X2
O
Oscillator Circuit Output.
Together with X1, 32.768kHz crystal is connected between them.
3
INT
O
Interrupt Output.
Open drain, active low.
4
GND
P
Ground.
Serial Data Input/Output.
SDA is the input/output pin for the 2-wire serial interface. The
SDA pin is open-drain output and requires an external pull-up resistor.
Serial Clock Input.
SCL is used to synchronize data movement on the I
2
C serial interface.
Clock Output.
Open drain. Four frequencies selectable: 32.768k, 1.024k, 32, 1Hz when
SQWE bit is set to 1.
Power.
5
6
7
SDA
SCL
SQW
I/O
I
O
8
VCC
P
3
RayStar Microelectronics Technology Inc.
(Integration Technology Advanced Inc.)
Ver: 1.4
Product Datasheet
IT8563
Real Time Clock
Function Description
Overview of Functions
1.
Clock function
CPU can read or write data including the year (last two digits), month, date, day, hour, minute, and second. Any (two-digit) year
that is a multiple of 4 is treated as a leap year and calculated automatically as such until the year 2100.
2.
Alarm function
These devices have one alarm system that outputs interrupt signals from INT of IT8563 when the date, day of the week, hour,
minute or second correspond to the setting. Each of them may output interrupt signal separately at a specified time. The alarm
may be selectable between on and off for matching alarm or repeating alarm.
3.
Programmable square wave output
A square wave output enable bit controls square wave output at pin 7. 4 frequencies are selectable: 1, 32, 1.024k, 32.768k Hz.
4.
Interface with CPU
Data is read and written via the I
2
C bus interface using two signal lines: SCL (clock) and SDA (data).
Since the output of the I/O pin SDA is open drain, a pull-up resistor should be used on the circuit board if the CPU output I/O is
also open drain.
The SCL's maximum clock frequency is 400 kHz, which supports the I
2
C bus's high-speed mode.
5.
Oscillator fail detect
When oscillator fail, OSF bit will be set.
6.
Oscillator enable/disable
Only time count chain can be enable or disable by STOP bit.
7.
Reset function
The IT8563 includes an internal reset circuit which is active whenever the oscillator is stopped. In the reset state the I
2
C-bus logic
is initialized and all registers, including the address pointer, are cleared with the exception of bits FE, OSF, TD1, TD0, TESTC
and AE which are set to logic 1.
4
RayStar Microelectronics Technology Inc.
(Integration Technology Advanced Inc.)
Ver: 1.4
Product Datasheet
IT8563
Real Time Clock
Registers
1.
Allocation of registers
Function (time range
BCD format)
Control/status 1
Control/status 2
Seconds (00-59)
Minutes (00-59)
Hours (00-23)
Dates (01-31)
Days of the week (00-06)
Months (01-12)
Years (00-99)
Alarm: Minutes (00-59)
Alarm: Hours (01-12)
Alarm: Dates (01-31)
Alarm: Weekday (00-06)
SQW control
Register definition
Bit 7
OSF
*4
Y80
AE
*5
AE
*5
AE
*5
AE
*5
SQWE
Bit 6
S40
M40
Y40
M40
Bit 5
S20
M20
H20
D20
Y20
M20
H20
D20
Bit 4
S10
M10
H10
D10
MO10
Y10
M10
H10
D10
Bit 3
AF
*2
S8
M8
H8
D8
MO8
Y8
M8
H8
D8
Bit 2
S4
M4
H4
D4
W4
MO4
Y4
M4
H4
D4
W4
Bit 1
AIE
*3
S2
M2
H2
D2
W2
MO2
Y2
M2
H2
D2
W2
RS1
Bit 0
S1
M1
H1
D1
W1
MO1
Y1
M1
H1
D1
W1
RS0
Addr.
(hex)
*1
00
01
02
03
04
05
06
07
08
09
0A
0B
0C
0D
Caution points:
*1. IT8563 uses 8 bits for address. For excess 0FH address, IT8563 will not respond.
*2. Alarm interrupt flag bits.
*3. Alarm interrupt enable bits.
*4. Oscillator fail indicates. Indicate clock integrity.
*5. Alarm enable bit. Alarm will be active when related time is matching if AE = 0.
*6. All bits marked with "" are not implemented.
5
RayStar Microelectronics Technology Inc.
(Integration Technology Advanced Inc.)
Ver: 1.4
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