PT7C4311 Datasheet, PDF (7/16 Pages) Pericom Semiconductor Corporation – Real-time Clock Module

PT7C4311
Real-time Clock Module (I²C Bus)
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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. Interface with CPU
2-wire I²C interface. The PT7C4311 continually monitors V_CC for an out of tolerance condition. Should V_CC fall below V_SO, the
device terminates an access in progress and resets the device address counter. Inputs to the device will not be recognized at this
time to prevent erroneous data from being written to the device from an out of tolerance system. When V_CC falls below V_SO, the
device automatically switches from battery to V_CC at V_SO and recognizes inputs.
3. Oscillator enable/disable
Oscillator and time count chain can be enabled or disabled at the same time by ST bit.
4. Calibration function
With the calibration bits properly set, accuracy PT7C4311 can be improved to better than ±2 ppm at 25°C.
Registers
1. Allocation of registers
Addr.
(hex) ^*1
Function
Register definition
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2 Bit 1 Bit 0
00 Seconds (00-59)
ST^*2
S40
01 Minutes (00-59)
02 Hours (00-23)

CEB^*3
M40
CB^*3
03 Days of the week (01-07)


04 Dates (01-31)


05 Months (01-12)


06 Years (00-99)
07
Control^*8
Y80
OUT^*4
Y40
FT^*5
S20
S10
S8
S4
S2
S1
M20
M10
M8
M4
M2
M1
H20
H10
H8
H4
H2
H1



W4
W2
W1
D20
D10
D8
D4
D2
D1
^*8
MO10 MO8
MO4 MO2 MO1
Y20
Y10
Y8
Y4
Y2
Y1
S^*6
Calibration^*7
2015-06-0002
PT0322-8
06/16/15
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