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Rainbow Electronics DS17487 User Manual

Page 14

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DS17485/DS17487

14 of 38

Table 2. PERIODIC INTERRUPT RATE AND SQUARE-WAVE OUTPUT
FREQUENCY

EXTENDED

REGISTER B

SELECT BITS REGISTER A

E32k RS3 RS2 RS1 RS0

t

PI

PERIODIC

INTERRUPT RATE

SQW OUTPUT

FREQUENCY

0

0 0 0 0

None

None

0

0 0 0 1

3.90625ms

256Hz

0

0 0 1 0

7.8125ms

128Hz

0

0 0 1 1

122.070µs

8.192kHz

0

0 1 0 0

244.141µs

4.096kHz

0

0 1 0 1

488.281µs

2.048kHz

0

0 1 1 0

976.5625µs

1.024kHz

0

0 1 1 1

1.953125ms

512Hz

0

1 0 0 0

3.90625ms

256Hz

0

1 0 0 1

7.8125ms

128Hz

0

1 0 1 0

15.625ms

64Hz

0

1 0 1 1

31.25ms

32Hz

0

1 1 0 0

62.5ms

16Hz

0

1 1 0 1

125ms

8Hz

0

1 1 1 0

250ms

4Hz

0

1 1 1 1

500ms

2Hz

1

X X X X

*

32.768kHz

*RS3 to RS0 determine periodic interrupt rates as listed for E32k = 0.