RA4803SA
Page - 22
ETM38E-03
8.5.2. Related registers
Address
Function
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
1
MIN
40
20
10
8
4
2
1
2
HOUR
20
10
8
4
2
1
3
WEEK
6
5
4
3
2
1
0
4
DAY
20
10
8
4
2
1
8
MIN Alarm
AE
40
20
10
8
4
2
1
9
HOUR Alarm
AE
•
20
10
8
4
2
1
A
WEEK Alarm
AE
6
5
4
3
2
1
0
DAY Alarm
•
20
10
8
4
2
1
D
Extension Register
TEST
WADA
USEL
TE
FSEL1
FSEL0
TSEL1
TSEL0
E
Flag Register
UF
TF
AF
EVF
VLF
VDET
F
Control Register
CSEL1
CSEL0
UIE
TIE
AIE
EIE
RESET
∗
1)
"o" indicates write-protected bits. A zero is always read from these bits.
∗
2)
Bits marked with "
•
" are RAM bits that can contain any value and are read/write-accessible.
∗
Before entering settings for operations, we recommend writing a "0" to the AIE bit to prevent hardware interrupts
from occurring inadvertently while entering settings.
∗
When the RESET bit value is "1"
alarm interrupt events do not occur.
∗
When the alarm interrupt function is not being used, the Alarm registers (Reg - 8 to A) can be used as a RAM
register. In such cases, be sure to write "0" to the AIE bit.
∗
When the AIE bit value is "1"
and the Alarm registers (Reg - 8 to A) is being used as a RAM register, /INT may
be changed to low level unintentionally.
1) WADA (Week Alarm /Day Alarm) bit
The alarm interrupt function uses either "Day" or "Week" as its target. The WADA bit is used to specify either
WEEK or DAY as the target for alarm interrupt events.
WADA
Data
Description
Write/Read
0
Sets WEEK as target of alarm function
(DAY setting is ignored)
1
Sets DAY as target of alarm function
(WEEK setting is ignored)
2) Alarm registers (Reg - 8 to A)
Address
Function
bit 7
bit 6
bit 5
bit 4
bit 3
bit 2
bit 1
bit 0
8
MIN Alarm
AE
40
20
10
8
4
2
1
9
HOUR Alarm
AE
•
20
10
8
4
2
1
A
WEEK Alarm
AE
6
5
4
3
2
1
0
DAY Alarm
•
20
10
8
4
2
1
The hour, minute, date or day when an alarm interrupt event will occur is set using this register and the
WADA bit.
In the WEEK alarm /Day alarm register (Reg - A), the setting selected via the WADA bit determines
whether WEEK alarm data or DAY alarm data will be set. If WEEK has been selected via the WADA bit,
multiple days can be set (such as Monday, Wednesday, Friday, Saturday).
When the settings made in the alarm registers and the WADA bit match the current time, the AF bit value
is changed to "1". At that time, if the AIE bit value has already been set to "1", the /INT pin goes low.
∗
1) The register that "1" was set to "AE" bit, doesn't compare alarm.
(Example) Write 80h (AE = "1") to the WEEK Alarm /DAY Alarm register (Reg - A):
Only the hour and minute settings are used as alarm comparison targets. The week and date settings
are not used as alarm comparison targets.
As a result, alarm occurs if only an hour and minute accords with alarm data.
∗
2) If all three AE bit values are "1" the week/date settings are ignored and an alarm interrupt event will
occur once per minute.
