HT1380A HOLTEK [Holtek Semiconductor Inc], HT1380A Datasheet - Page 7

• Manufacturer Part Number: HT1380A
• Description: Serial Timekeeper Chip
• Manufacturer: HOLTEK [Holtek Semiconductor Inc]

The following diagram shows the single and burst mode transfer:
Single Byte Transfer
Burst Mode Transfer
Crystal Specifications
Note: 1. It is strongly recommended to use a crystal with a load capacitance of 9.0pF. Never use a crystal with a
Operating Flowchart
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
f
ESR
C
O
L
Symbol
2. The oscillator selection can be optimized using a high quality resonator with a small ESR value. Refer to
load capacitance of 12.5pF.
the crystal manufacturer for more details: www.microcrystal.com.
Nominal Frequency
Series Resistance
Load Capacitance
R E S T
S C L K
R E S T
S C L K
I / O
I / O
Parameter
R / W
R / W
0
0
A 0
1
1
1
C o m m a n d B y t e
C o m m a n d B y t e
2
2
A 1 A 2
1
3
3
1
1
0
4
4
1
0
5
5
Min.
—
—
—
0
0
6
6
7
1
1
7
7
D a t a B y t e 0
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.
0
0
1
D a t a I / O
32.768
7
Typ.
2
9.0
—
3
4
5
D a t a B y t e 7
0
6
HT1380A/HT1381A
Max.
—
50
—
7
7
June 15, 2012
Unit
kHz
kΩ
pF