ISL12029 Intersil Corporation, ISL12029 Datasheet - Page 26

• Manufacturer Part Number: ISL12029
• Description: Real Time Clock/Calendar
• Manufacturer: Intersil Corporation

www.DataSheet4U.com
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.
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:
REGISTER
REGISTER
REGISTER
CONTROL
ALARM0
ALARM0
MNA0
MOA0
DWA0
HRA0
SCA0
DTA0
MNA0
MOA0
DWA0
SCA0
HRA0
DTA0
INT
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
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
7 6 5 4 3 2 1 0 HEX
0 0 1 0 0 0 0 0
BIT
BIT
BIT
26
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
DESCRIPTION
enabled
enabled
enabled
enabled
disabled
DESCRIPTION
DESCRIPTION
OUT
output
ISL12029
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
CONTROL
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
OUT
-:
BIT
60 sec
Mode
DESCRIPTION
April 17, 2006
FN6206.4