ACE5372

Low Power Real-Time Clock (RTC)

VER 1.3

11

CT2, CT1, CT0

Periodic interrupt cycle select bit

CT2

CT1

CT0

Description

Wave Form

Mode

Cycle and INTRA（INTRB）Falling Timing

0

0

0

-

INTRA（INTRB）at high level

0

0

1

-

INTRA（INTRB）at low level

0

1

0

Pulse Mode

2Hz（Duty 50%）

0

1

1

Pulse Mode

1Hz（Duty 50%）

1

0

0

Level Mode

Every second（synchronized with second count up）

1

0

1

Level Mode

Every minute（00 second of every minute）

1

1

0

Level Mode

Every hour（00 minute 00 second of every hour）

1

1

1

Level Mode

Every month（the 1

month）

1) Pulse mode: Outputs 2Hz, 1Hz clock pulses.

For relationships with counting up of seconds see the

diagram below.

In the 2Hz clock pulse mode, 0.496s clock pulses and 0.504s clock pulses are output alternatively.

Duty cycle for 1Hz clock pulses becomes 50.4%.

2) Level mode: One second, one minute or one month may be selected for an interrupt cycle. Counting up

of seconds is matched with falling edge of interrupt output.

3) When the time trimming circuit is used, periodic interrupt cycle changes every 20 seconds.

Pulse mode:“L” duration of output pulses may change in the maximum range of ±3.784ms (±3.875ms

when 32KHz crystal is used).

For example, Duty will be 50±0.3784% (or 50±0.3875% when 32KHz crystal is used) at 1Hz.

Level Mode: Frequency is one second may change in the maximum range of ±3.784ms (±3.875ms

when 32KHz crystal is used).

Relation Between Mode Waveforms and CRFG Bit



Pulse mode