DS1202, DS1202S

032697 4/11

REGISTER SUMMARY

A register data format summary is shown in Figure 4.

CRYSTAL SELECTION

A 32.768 KHz crystal, can be directly connected to the

DS1202 via pins 2 and 3 (X1, X2). The crystal selected

for use should have a specified load capacitance (CL) of

6 pF. The crystal is connected directly to the X1 and X2

pins. There is no need for external capacitors or resis-

tors. Note: X1 and X2 are very high impedance nodes.

It is recommended that they and the crystal be guard–

ringed with ground and that high frequency signals be

kept away from the crystal area. For more information

on crystal selection and crystal layout considerations,

please consult Application Note 58, “Crystal Consider-

ations with Dallas Real Time Clocks”.

DATA TRANSFER SUMMARY Figure 3

SCLK

I/O

RST

01

2

3456

701

234

5

6

7

R/W

A0

A1

A2

A3

A4

1

ADDRESS COMMAND

DATA INPUT/OUTPUT

SINGLE BYTE TRANSFER

SCLK

I/O

01

2

3456

701

2

4

5

6

7

1

1

111

1

ADDRESS COMMAND

DATA I/O BYTE N

BURST MODE TRANSFER

RST

R/W

DATA I/O BYTE 1

R/C

R/C

FUNCTION

BYTE N

SCLK n

CLOCK

8

72

RAM

24

200