BQ3285EC Datasheet, PDF (9/26 Pages) Texas Instruments – Real-Time Clock (RTC)

bq3285EC/LC
Register B
Register B Bits
7
6
5
4
3
2
UTI PIE AIE UIE - DF
1
0
HF DSE
Register B enables:
n Update cycle transfer operation
n Interrupt events
n Daylight saving adjustment
Register B selects:
n Clock and calendar data formats
All bits of register B are read/write.
Bit 3 - Unused Bit.
DSE - Daylight Saving Enable
7
6
5
4
3
2
1
0
-
-
-
-
-
-
- DSE
This bit enables daylight-saving time adjustments when
written to 1:
n On the last Sunday in October, the first time the
bq3285EC/LC increments past 1:59:59 AM, the time
falls back to 1:00:00 AM.
n On the first Sunday in April, the time springs
forward from 2:00:00 AM to 3:00:00 AM.
HF - Hour Format
7
6
5
4
3
2
1
0
-
-
-
-
-
- HF -
This bit selects the time-of-day and alarm hour format:
1 = 24-hour format
0 = 12-hour format
DF - Data Format
7
6
5
4
-
-
-
-
3
2
1
0
- DF -
-
UIE - Update Cycle Interrupt Enable
7
6
5
4
3
2
1
0
-
-
- UIE -
-
-
-
This bit enables an interrupt request due to an update
ended interrupt event:
1 = Enabled
0 = Disabled
The UIE bit is automatically cleared when the UTI bit
equals 1.
AIE - Alarm Interrupt Enable
7
6
5
4
3
2
1
0
-
- AIE -
-
-
-
-
This bit enables an interrupt request due to an alarm
interrupt event:
1 = Enabled
0 = Disabled
PIE - Periodic Interrupt Enable
7
6
5
4
3
2
1
0
- PIE -
-
-
-
-
-
This bit enables an interrupt request due to a periodic
interrupt event:
1 = Enabled
0 = Disabled
UTI - Update Transfer Inhibit
7
6
5
4
3
2
1
0
UTI -
-
-
-
-
-
-
This bit inhibits the transfer of RTC bytes to the user
buffer:
1 = Inhibits transfer and clears UIE
0 = Allows transfer
This bit selects the numeric format in which the time,
alarm, and calendar bytes are represented:
1 = Binary
0 = BCD
July 1996
9