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PT0222(02/06)

Ver: 0

5

Data Sheet

PT7C4300

Real-time Clock Module (I

Registers

1.

Allocation of registers

Register definition

Addr.

(hex)

*1

Function

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

00

Seconds (00-59)

ST

*2

S40

S20

S10

S8

S4

S2

S1

01

Minutes (00-59)

×

M40

M20

M10

M8

M4

M2

M1

02

Hours (00-23)

CEB

*3

CB

*3

H20

H10

H8

H4

H2

H1

03

Days of the week (01-07)

×

×

×

×

×

W4

W2

W1

04

Dates (01-31)

×

×

D20

D10

D8

D4

D2

D1

05

Months (01-12)

×

×

MO10

MO8

MO4

MO2

MO1

06

Years (00-99)

Y80

Y40

Y20

Y10

Y8

Y4

Y2

Y1

07

Control

*3

OUT

*4

FT

*5

S

*6

Calibration

*7

Caution points:

*1. PT7C4300 uses 3 bits for address. That is if write data to 08H, the data will be written to 00H address register.

*2. Stop bit. When this bit is set to 1, oscillator and time count chain are both stopped.

*3. CEB: Century Enable Bit. CB: Century Bit.

*4. Control FT/OUT pin output DC level when 512Hz square wave is disabled.

*5. Frequency Test. 512Hz square wave output is enabled at FT/OUT pin, which is using for frequency test.

*6. Sign Bit. “1” indicates positive calibration; “0”indicates negative calibration.

*7. Using for modifying count frequency. If 20ppm is wanted to slow down the count frequency, 10 (01010) should be loaded.

Calibration will not affect FT/OUT output frequency.

*8.

Don’t care.