HOLTEK HT1381A

HT1380A/HT1381A
Serial Timekeeper Chip
Features
General Description
• Operating voltage: 2.0V~5.5V
The HT1380A/HT1381A is a serial timekeeper IC
which provides seconds, minutes, hours, day, date,
month and year information. The number of days in
each month and leap years are automatically adjusted.
The HT1380A/HT1381A is designed for low power
consumption and can operate in two modes: one is the
12-hour mode with an AM/PM indicator, the other is
the 24-hour mode.
• Maximum input serial clock: 500kHz at VDD=2V,
2MHz at VDD=5V
• Operating current:
–– less than 0.5μA at 2V
–– less than 0.7μA at 3V
–– less than 1.0μA at 5V
• TTL compatible
–– VIH: 2.0V~VDD+0.3V at VDD=5V
–– VIL: 0.3V~+0.8V at VDD=5V
The HT1380A/HT1381A has several registers to
store the corresponding information with 8-bit data
format. A 32768Hz crystal is required to provide the
correct timing. In order to minimize the pin number,
the HT1380A/HT1381A use a serial I/O transmission
method to interface with a microprocessor. Only three
wires are required: (1) REST, (2) SCLK and (3) I/O.
Data can be delivered 1 byte at a time or in a burst of
up to 8 bytes.
• Two data transmission modes: single-byte, or burst
mode
• Serial I/O transmission
• All registers store BCD format
• HT1380A: 8-pin DIP package
HT1381A: 8-pin SOP package
Applications
• Microcomputer serial clock
• Clock and Calendar
Block Diagram
  Pin Assignment
Rev. 1.00
1
June 15, 2012
HT1380A/HT1381A
Pad Assignment
N C
1
N C
3
2
N C
4
V S S
(0 ,0 )
X 1
5
X 2
V S S
6
7
1 1
V D D
1 0
S C L K
9
I/O
8
R E S T
Chip size: 1136 × 900 (μm)2
* The IC substrate should be connected to VSS in the PCB layout artwork.
Pad Coordinates
Unit: μm
Pad No.
X
Y
1
-456.985
333.025
2
-456.985
264.025
3
-456.985
195.025
4
-455.590
109.935
5
-466.000
-154.955
6
-466.000
-249.955
7
-466.000
-344.955
8
465.966
-309.630
9
465.966
-214.630
10
465.966
-119.630
11
465.966
-24.630
Pad Description
Pin Name
I/O
Internal Connection
VSS
�
CMOS
Negative power supply, ground
X1
I
CMOS
32768Hz crystal input pad
X2
O
CMOS
Oscillator output pad
REST
I
CMOS
Reset pin with serial transmission
I/O
I/O
CMOS
Data Input/Output pin with serial transmission
SCLK
I
CMOS
Serial Clock pulse pin with serial transmission
VDD
�
CMOS
Positive power supply
Rev. 1.00
Description
2
June 15, 2012
HT1380A/HT1381A
Absolute Maximum Ratings
Supply Voltage ........................................ -0.3V ~ 5.5V
Storage Temperature .............................-50˚C ~ 125˚C
Input Voltage.............................. VSS-0.3V ~ VDD+0.3V
Operating Temperature............................-40˚C ~ 85˚C
Note: These are stress ratings only. Stresses exceeding the range specified under “Absolute Maximum Ratings”
may cause substantial damage to the device. Functional operation of this device at other conditions beyond
those listed in the specification is not implied and prolonged exposure to extreme conditions may affect
device reliability.
D.C. Characteristics
Symbol
Parameter
Ta=25˚C
Test Conditions
Min.
Typ.
Max.
—
—
100
—
—
100
5V
—
—
100
2V
—
0.30
0.50
—
0.50
0.70
—
0.85
1.00
VDD
Conditions
2V
ISTB
IDD
Standby Current
Operating Current
3V
3V
—
No load
5V
IOH
IOL
Source Current
Sink Current
VIH
"H" Input Voltage
VIL
"L" Input Voltage
2V
VOH=1.8V
-0.20
-0.40
—
3V
VOH=2.7V
-0.35
-0.70
—
5V
VOH=4.5V
-0.50
-1.00
—
2V
VOL=0.2V
0.70
1.50
—
3V
VOL=0.3V
1.20
2.50
—
5V
VOL=0.5V
2.00
4.00
—
2.00
—
—
2.00
—
—
—
—
0.60
—
—
0.80
3V
5V
3V
5V
—
—
Unit
nA
μA
mA
mA
V
V
Note: ISTB is specified with SCLK, I/O, REST open. The clock halt bit must be set to logic 1 (oscillator disabled).
Rev. 1.00
3
June 15, 2012
HT1380A/HT1381A
A.C. Characteristics
Symbol
tDC
tCDH
tCDD
tCL
tCH
fSCLK
tr/tf
tCC
tCCH
tCWH
tCDZ
Rev. 1.00
Parameter
Data to Clock Setup
Clock to Data Hold
Clock to Data Delay
Clock Low Time
Clock High Time
Clock Frequency
Clock Rise and Fall Time
Reset to Clock Setup
Clock to Reset Hold
Reset Inactive Time
Reset to I/O High Impedance
Ta=25˚C
Test Conditions
Min.
Typ.
Max.
—
200
—
—
—
100
—
—
5V
—
50
—
—
2V
—
280
—
—
3V
—
140
—
—
5V
—
70
—
—
2V
—
—
—
800
3V
—
—
—
400
5V
—
—
—
200
2V
—
1000
—
—
3V
—
500
—
—
5V
—
250
—
—
2V
—
1000
—
—
3V
—
500
—
—
5V
—
250
—
—
2V
—
—
—
0.5
3V
—
—
—
1.0
5V
—
—
—
2.0
2V
—
—
—
2000
3V
—
—
—
1000
5V
—
—
—
500
2V
—
4
—
—
3V
—
2
—
—
5V
—
1
—
—
2V
—
240
—
—
3V
—
120
—
—
5V
—
60
—
—
2V
—
4
—
—
3V
—
2
—
—
5V
—
1
—
—
2V
—
—
—
280
3V
—
—
—
140
5V
—
—
—
70
VDD
Conditions
2V
3V
4
Unit
ns
ns
ns
ns
ns
MHz
ns
μs
ns
μs
ns
June 15, 2012
HT1380A/HT1381A
Functional Description
data can be written to the register array. These two
bits should first be specified in order to read from and
write to the register array properly.
The HT1380A/HT1381A mainly contains the
following internal elements: a data shift register array
to store the clock/calendar data, command control
logic, oscillator circuit and read timer clock. The
clock is contained in eight read/write registers as
shown below. Data contained in the clock register is
in binary coded decimal format.
Command Byte
For each data transfer, a Command Byte is initiated
to specify which register is accessed. This is to
determine whether a read, write, or test cycle is
operated and whether a single byte or burst mode
transfer is to occur. Refer to the table shown below
and follow the steps to write the data to the chip. First
give a Command Byte of HT1380A/HT1381A, and
then write a data in the register.
Two modes are available for transferring the data
between the microprocessor and the HT1380A/
HT1381A. One is in single-byte mode and the other is
in multiple-byte mode.
This table illustrates the correlation between
Command Byte and their bits:
The HT1380A/HT1381A also contains two additional
bits, the clock halt bit (CH) and the write protect bit (WP).
These bits control the operation of the oscillator and so
Command Byte
Function Description
C7
C6
C5
C4
C3
C2
C1
C0
Select Read or Write Cycle
—
—
—
—
—
—
—
R/W
Specify the Register to be Accessed
—
—
—
—
A2
A1
A0
—
Clock Halt Flag
C
—
—
—
—
—
—
—
For IC Test Only
1
0
0
1
x
x
x
1
Select Single Byte or Burst Mode
1
0
1
1
1
1
1
x
Note: ″x″ stands for don′t care
The following table shows the register address and its data format:
Register
Name
Register Definition
Range
Data
D7
Address
A2~A0
Bit
R/W
Command
Byte
Seconds
00~59
CH
10 SEC
SEC
000
W
R
10000000
10000001
Minutes
00~59
0
10 MIN
MIN
001
W
R
10000010
10000011
Hours
01~12
00~23
12\
24
0
0
AP
10
HR
HR
HOUR
010
W
R
10000100
10000101
Date
01~31
0
0
10 DATE
DATE
011
W
R
10000110
10000111
Month
01~12
0
0
0
10M
MONTH
100
W
R
10001000
10001001
Day
01~07
0
0
0
0
DAY
101
W
R
10001010
10001011
Year
00~99
YEAR
110
W
R
10001100
10001101
Write Protect
00~80
111
W
R
10001110
10001111
D6
D5
D4
D3
D2
10 YEAR
WP
ALWAYS ZERO
D1
D0
CH: Clock Halt bit
CH=0 oscillator enabled
CH=1 oscillator disabled
Bit 7 of Reg2: 12/24 mode flag
bit 7=1, 12-hour mode
bit 7=0, 24-hour mode
WP: Write protect bit
WP=0 register data can be written in
WP=1 register data can not be written in
Bit 5 of Reg2: AM/PM mode defined
AP=1 PM mode
AP=0 AM mode
Rev. 1.00
5
June 15, 2012
HT1380A/HT1381A
R/W Signal
AM-PM Mode
The LSB of the Command Byte determines whether
the data in the register be read or be written to.
These are two functions for the D5 of the hour register
determined by the value D7 of the same register.
When it is set as ″0″ means that a write cycle is to take
place otherwise this chip will be set into the read mode.
One is used in AM/PM selection on the 12-hour
mode. When D5 is logic 1, it is PM, otherwise it′s
AM. The other is used to set the second 10-hour bit
(20~23 hours) on the 24-hour mode.
A0~A2
A0 to A2 of the Command Byte is used to specify
which registers are to be accessed. There are eight
registers used to control the month data, etc., and each
of these registers have to be set as a write cycle in the
initial time.
Reset and Serial Clock Control
The REST pin is used to allow access data to the shift
register like a toggle switch. When the REST pin
is taken high, the built-in control logic is turned on
and the address/command sequence can access the
corresponding shift register. The REST pin is also
used to terminate either single-byte or burst mode
data format.
Burst Mode
When the Command Byte is 10111110 (or 10111111),
the HT1380A/HT1381A is configured in burst mode.
In this mode the eight clock/calendar registers can
be written (or read) in series, starting with bit 0 of
register address 0 (see the timing on the next page).
The input signal of SCLK is a sequence of a falling
edge followed by a rising edge and it is used to
synchronize the register data whether read or write.
For data input, the data must be read after the rising
edge of SCLK. The data on the I/O pin becomes
output mode after the falling edge of the SCLK. All
data transfer terminates if the REST pin is low and
the I/O pin goes to a high impedance state. The data
transfer is illustrated on the next page.
Test Mode
When the Command Byte is set as 1001xxx1,
HT1380A/HT1381A is configured in test mode. The
test mode is used by Holtek only for testing purposes.
If used generally, unpredictable conditions may occur.
Data Input and Data Out
Write Protect Register
In writing a data byte with HT1380A/HT1381A, the
read/write should first set as R/W=0 in the Command
Byte and follow with the corresponding data register
on the rising edge of the next eight SCLK cycles.
Additional SCLK cycles are ignored. Data inputs are
entered starting with bit 0.
This register is used to prevent a write operation
to any other register. Data can be written into the
designated register only if the Write Protect signal
(WP) is set to logic 0. The Write Protect Register
should be set first before restarting the system or
before writing the new data to the system, and it
should set as logic 1 in the read cycle. The Write
Protect bit cannot be written to in the burst mode.
In reading a data on the register of HT1380A/
HT1381A, R/W=1 should first be entered as input.
The data bit outputs on the falling edge of the next
eight SCLK cycles. Note that the first data bit to be
transmitted on the first falling edge after the last bit of
the read command byte is written. Additional SCLK
cycles re-transmits the data bytes as long as REST
remains at high level. Data outputs are read starting
with bit 0.
Clock HALT Bit
D7 of the Seconds Register is defined as the Clock
Halt Flag (CH).
When this bit is set to logic 1, the clock oscillator is
stopped and the chip goes into a low-power standby
mode. When this bit is written to logic 0, the clock
will start.
Crystal Selection
A 32768Hz crystal can be directly connected to the
HT1380A/HT1381A on pins 2 and 3 which are the
crystal X1 and X2 pins. In order to ensure that the
desired frequency is achieved, it is recommended
to use a crystal with a capacitance of 9.0pF. It is
not recommended that additional load capacitors
are connected to the X1 and X2 pins. Refer to the
following page for the crystal specifications.
12-hour/24-hour Mode
The D7 of the hour register is defined as the 12-hour
or 24-hour mode select bit.
When this bit is in high level, the 12-hour mode is
selected otherwise it′s the 24-hour mode.
Rev. 1.00
6
June 15, 2012
HT1380A/HT1381A
The following diagram shows the single and burst mode transfer:
Single Byte Transfer
S C L K
R E S T
0
I/O
R /W
1
2
3
A 0
A 1
A 2
4
5
0
6
0
7
0
0
1
2
3
4
5
6
7
1
C o m m a n d B y te
D a ta I/O
Burst Mode Transfer
S C L K
R E S T
0
I/O
R /W
1
1
2
1
3
1
4
1
5
1
6
0
7
0
7
0
7
1
C o m m a n d B y te
D a ta B y te 0
D a ta B y te 7
Crystal Specifications
Symbol
Parameter
Min.
Typ.
Max.
Unit
fO
Nominal Frequency
—
32.768
—
kHz
ESR
Series Resistance
—
—
50
kΩ
CL
Load Capacitance
—
9.0
—
pF
Note: 1. It is strongly recommended to use a crystal with a load capacitance of 9.0pF. Never use a crystal with a
load capacitance of 12.5pF.
2. The oscillator selection can be optimized using a high quality resonator with a small ESR value. Refer to
the crystal manufacturer for more details: www.microcrystal.com.
Operating Flowchart
In using the HT1380A/HT1381A, set first the WP and
CH to 0 and wait for about 3 seconds, the oscillator
will generate the clocks for internal use. Then, choose
either single mode or burst mode to input the data.
The read or write operating flowcharts are shown on
the next page.
To initiate any transfer of data, REST is taken high and
an 8-bit command byte is first loaded into the control
logic to provide the register address and command
information. Following the command word, the clock/
calendar data is serially transferred to or from the
corresponding register. The REST pin must be taken
low again after the transfer operation is completed. All
data enter on the rising edge of SCLK and outputs on
the falling edge of SCLK. In total, 16 clock pulses are
needed for a single byte mode and 72 for burst mode.
Both input and output data starts with bit 0.
Rev. 1.00
7
June 15, 2012
HT1380A/HT1381A
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  ‰   Note: * In reading data byte from HT1380A/HT1381A register, the first data bit to be transmitted at the first falling
edge after the last bit of the command byte is written.
Rev. 1.00
8
June 15, 2012
HT1380A/HT1381A
Timing Diagrams
Read Data Transfer
R E S T
tC C
S C L K
tC D H
tC D D
tD C
7
0
I/O
tC D Z
7
0
C o m m a n d B y te
O u tp u t D a ta B y te
Write Data Transfer
tC W H
R E S T
S C L K
tC D H
tD C
tC C H
tf
tC L
7
0
I/O
tr
tC H
tC C
7
0
C o m m a n d B y te
In p u t D a ta B y te
Application Circuit
Note: * In order to obtain the correct frequency, it is recommended to use a crystal with a load capacitance of
9.0pF. It is not recommended to connect load capacitors to the X1 and X2 pins. If the power line is noisy, it
is recommended to add R1 and C1 for filtering out noise.
Rev. 1.00
9
June 15, 2012
HT1380A/HT1381A
Package Information
Note that the package information provided here is for consultation purposes only. As this information may be
updated at regular intervals users are reminded to consult the Holtek website (http://www.holtek.com.tw/english/
literature/package.pdf) for the latest version of the package information.
8-pin DIP (300mil) Outline Dimensions
Symbol
Min.
Nom.
Max.
A
0.355
―
0.375
B
0.240
―
0.260
C
0.125
―
0.135
D
0.125
―
0.145
E
0.016
―
0.020
F
0.050
―
0.070
G
―
0.100
―
H
0.295
―
0.315
I
―
0.375
―
Symbol
Rev. 1.00
Dimensions in inch
Dimensions in mm
Min.
Nom.
Max.
A
9.02
―
9.53
B
6.10
―
6.60
C
3.18
―
3.43
D
3.18
―
3.68
E
0.41
―
0.51
F
1.27
―
1.78
G
―
2.54
―
H
7.49
―
8.00
I
―
9.53
―
10
June 15, 2012
HT1380A/HT1381A
8-pin SOP (150mil) Outline Dimensions
MS-012
Symbol
Min.
Nom.
Max.
A
0.228
―
0.244
B
0.150
―
0.157
C
0.012
―
0.020
C'
0.188
―
0.197
D
―
―
0.069
E
―
0.050
―
F
0.004
―
0.010
G
0.016
―
0.050
H
0.007
―
0.010
α
0°
―
8°
Symbol
Rev. 1.00
Dimensions in inch
Dimensions in mm
Min.
Nom.
Max.
A
5.79
―
6.20
B
3.81
―
3.99
C
0.30
―
0.51
C'
4.78
―
5.00
D
―
―
1.75
E
―
1.27
―
F
0.10
―
0.25
G
0.41
―
1.27
H
0.18
―
0.25
α
0°
―
8°
11
June 15, 2012
HT1380A/HT1381A
Reel Dimensions
SOP 8N (150mil)
Symbol
Description
Dimensions in mm
A
Reel Outer Diameter
B
Reel Inner Diameter
100.0±1.5
C
Spindle Hole Diameter
13.0 +0.5/-0.2
D
Key Slit Width
T1
Space Between Flange
T2
Reel Thickness
Rev. 1.00
330.0±1.0
2.0±0.5
12.8 +0.3/-0.2
18.2±0.2
12
June 15, 2012
HT1380A/HT1381A
Carrier Tape Dimensions
 SOP 8N (150mil)
Symbol
Description
W
Carrier Tape Width
Dimensions in mm
12.0 +0.3/-0.1
P
Cavity Pitch
E
Perforation Position
1.75±0.10
8.0±0.1
5.50±0.1
F
Cavity to Perforation (Width Direction)
D
Perforation Diameter
1.55±0.1
D1
Cavity Hole Diameter
1.50 +0.25/-0.00
P0
Perforation Pitch
4.0±0.1
P1
Cavity to Perforation (Length Direction)
2.0±0.1
A0
Cavity Length
6.4±0.1
B0
Cavity Width
5.2±0.1
K0
Cavity Depth
t
Carrier Tape Thickness
C
Cover Tape Width
Rev. 1.00
2.1±0.1
0.30±0.05
9.3±0.1
13
June 15, 2012
HT1380A/HT1381A
Holtek Semiconductor Inc. (Headquarters)
No.3, Creation Rd. II, Science Park, Hsinchu, Taiwan
Tel: 886-3-563-1999
Fax: 886-3-563-1189
http://www.holtek.com.tw
Holtek Semiconductor Inc. (Taipei Sales Office)
4F-2, No. 3-2, YuanQu St., Nankang Software Park, Taipei 115, Taiwan
Tel: 886-2-2655-7070
Fax: 886-2-2655-7373
Fax: 886-2-2655-7383 (International sales hotline)
Holtek Semiconductor Inc. (Shenzhen Sales Office)
5F, Unit A, Productivity Building, No.5 Gaoxin M 2nd Road, Nanshan District, Shenzhen, China 518057
Tel: 86-755-8616-9908, 86-755-8616-9308
Fax: 86-755-8616-9722
Holtek Semiconductor (USA), Inc. (North America Sales Office)
46729 Fremont Blvd., Fremont, CA 94538, USA
Tel: 1-510-252-9880
Fax: 1-510-252-9885
http://www.holtek.com
Copyright© 2012 by HOLTEK SEMICONDUCTOR INC.
The information appearing in this Data Sheet is believed to be accurate at the time of publication.
However, Holtek assumes no responsibility arising from the use of the specifications described.
The applications mentioned herein are used solely for the purpose of illustration and Holtek makes
no warranty or representation that such applications will be suitable without further modification,
nor recommends the use of its products for application that may present a risk to human life due to
malfunction or otherwise. Holtek's products are not authorized for use as critical components in life
support devices or systems. Holtek reserves the right to alter its products without prior notification. For
the most up-to-date information, please visit our web site at http://www.holtek.com.tw.
Rev. 1.00
14
June 15, 2012