ACE5372

Low Power Real-Time Clock (RTC)

VER 1.2

8

For example, when 32.768KHz crystal is used. When (F6, F5, F4, F3, F2, F1, F0) are set to (0,1, 0, 1,

0, 0,1), counts will change as: 32768+（29-1）*2=32824 (clock will be delayed) when second digit is 00, 20,

or 40.When (F6, F5, F4, F3, F2, F1, F0) are set to (0, 0, 0, 0, 0, 0, 1), counts will remain 32,768 without

changing when second digit is 00, 20, or 40. When (F6, F5, F4, F3, F2, F1, F0) are set to (1,1,0,1,0,0,1),

counts will change as: 32768+（-17+1）*2=32736 (clock will be advanced) when second digit is 00, 20, or

40.

Adding 2 clock pulses every 20 seconds: 2/ （ 32768*20 ） =3.051ppm (or 3.125ppm when

32.000KHZcrystal is used), delays the clock by approx. 3ppm. Likewise, decrementing 2 clock pulses

advances the clock by 3ppm. Thus the clock may be adjusted to the precision of±1.5ppm. Note that the

time trimming function only adjusts clock timing and oscillation frequency but 32.768KHz clock output is

not adjusted.

5. Alarm Register (Alarm-A : internal address 8-AH; Alarm-B : internal address B-DH)

Alarm-A minute register (at internal address 8H)

D7

D6

D5

D4

D3

D2

D1

D0

Operation

-

AM40

AM20

AM10

AM8

AM4

AM2

AM1

Write

0

AM40

AM20

AM10

AM8

AM4

AM2

AM1

Read

0

Undefined

Undefined

Undefined

Undefined

Undefined

Undefined

Undefined

Default

Alarm-B minute register (at internal address BH)

D7

D6

D5

D4

D3

D2

D1

D0

Operation

-

BM40

BM20

BM10

BM8

BM4

BM2

BM1

Write

0

BM40

BM10

BM10

BM8

BM4

BM2

BM1

Read

0

Undefined

Undefined

Undefined

Undefined

Undefined

Undefined

Undefined

Default

Alarm-A hour register (at internal address 9H)

D7

D6

D5

D4

D3

D2

D1

D0

Operation

-

-

AH20,AP/

⎯A

AH10

AH8

AH4

AH2

AH1

Write

0

-

AH20,AP/

⎯A

AH10

AH8

AH4

AH2

AH1

Read

0

0

Undefined

Undefined

Undefined

Undefined

Undefined

Undefined

Default

Alarm-B hour register (at internal address CH)

D7

D6

D5

D4

D3

D2

D1

D0

Operation

-

-

BH20,BP/

⎯A

BH10

BH8

BH4

BH2

BH1

Write

0

0

BH20,BP/

⎯A

BH10

BH8

BH4

BH2

BH1

Read

0

0

Undefined

Undefined

Undefined

Undefined

Undefined

Undefined

Default

Alarm-A day-of-week register (at internal address AH)

D7

D6

D5

D4

D3

D2

D1

D0

Operation

-

AW6

AW5

AW4

AW3

AW2

AW1

AW0

Write

0

AW6

AW5

AW4

AW3

AW2

AW1

AW0

Read

0

Undefined

Undefined

Undefined

Undefined

Undefined

Undefined

Undefined

Default