ISL12028 Intersil Corporation, ISL12028 Datasheet - Page 26

• Manufacturer Part Number: ISL12028
• Manufacturer: Intersil Corporation

Alarm Operation Examples
Below are examples of both Single Event and periodic
Interrupt Mode alarms.
Example 1 – Alarm 0 set with single interrupt (IM = ”0”)
A single alarm will occur on January 1 at 11:30am.
A. Set Alarm 0 registers as follows:
B. Also the AL0E bit must be set as follows:
After these registers are set, an alarm will be generated when
the RTC advances to exactly 11:30am on January 1 (after
seconds changes from 59 to 00) by setting the AL0 bit in the
status register to “1” and also bringing the IRQ/F
low.
REGISTER
REGISTER
CONTROL
ALARM0
MOA0
DWA0
MNA0
HRA0
SCA0
DTA0
INT
V
7 6 5 4 3 2 1 0 HEX
0 0 0 0 0 0 0 0
1 0 1 1 0 0 0 0
1 0 0 1 0 0 0 1
1 0 0 0 0 0 0 1
1 0 0 0 0 0 0 1
0 0 0 0 0 0 0 0
I
7 6 5 4 3 2 1 0 HEX
0 0 1 0 0 0 0 0
DD
BAT
RESET
V
(2.2V)
TRIP
V
RESET
BIT
BIT
26
(2.63V)
V
BAT
(3.0V)
B0h Minutes set to 30,
00h Seconds disabled
91h Hours set to 11,
81h Date set to 1,
81h Month set to 1,
00h Day of week
x0h Enable Alarm
enabled
enabled
enabled
enabled
disabled
FIGURE 30. RESET OPERATION IN MODE D
DESCRIPTION
DESCRIPTION
OUT
tPURST
output
ISL12028
I
2
C Bus Active
Example 2 – Pulsed interrupt once per minute (IM = ”1”)
Interrupts at one minute intervals when the seconds register
is at 30 seconds.
A. Set Alarm 0 registers as follows:
B. Set the Interrupt register as follows:
XX indicate other control bits.
Once the registers are set, the following waveform will be
seen at IRQ/F
Note that the status register AL0 bit will be set each time the
alarm is triggered, but does not need to be read or cleared.
REGISTER
REGISTER
CONTROL
ALARM0
DWA0
MNA0
MOA0
SCA0
HRA0
DTA0
INT
RTC and alarm registers are both “30” sec
7 6 5 4 3 2 1 0 HEX
1 0 1 x x 0 0 0 x0h Enable Alarm and Int
7 6 5 4 3 2 1 0 HEX
1 0 1 1 0 0 0 0 B0h Seconds set to 30,
0 0 0 0 0 0 0 0 00h Minutes disabled
0 0 0 0 0 0 0 0 00h Hours disabled
0 0 0 0 0 0 0 0 00h Date disabled
0 0 0 0 0 0 0 0 00h Month disabled
0 0 0 0 0 0 0 0 00h Day of week disabled
OUT
-:
BIT
BIT
60 sec
(Battery backup mode)
Mode
enabled
DESCRIPTION
DESCRIPTION
April 17, 2006
FN8233.3