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RA8804 CE
8.6.2. Related registers for time update interrupt functions.
Address
Function
0D
Extension Register
0E
Flag Register
0F
Control Register
)o indicates write-protected bits. A zero is always read from these bits.
Before entering settings for operations, we recommend writing a "0" to the UIE bit to prevent hardware interrupts
from occurring inadvertently while entering settings.
When the RESET bit value is 1time update interrupt events do not occur.
Although the time update interrupt function cannot be fully stopped, if "0" is written to the UIE bit, the time update
interrupt function can be prevented from changing the /INT pin status to low.
1) USEL (Update Interrupt Select) bit
This bit is used to select "second" update or "minute" update as the timing for generation of time update interrupt
events.
USEL
Write/Read
2) UF (Update Flag) bit
Once it has been set to "0", this flag bit value changes from "0" to "1" when a time update interrupt event occurs.
When this flag bit = "1" its value is retained until a "0" is written to it.
UF
Write
Read
3) UIE (Update Interrupt Enable) bit
When a time update interrupt event occurs (UF bit value changes from "0"to"1"), this bit selects whether to
generate an interrupt signal (/INT status changes from Hi-Z to low) or to not generate it (/INT status remains Hi-Z).
UIE
Write/Read
bit 7
bit 6
USEL
TEST
WADA
CSEL1
CSEL0
Data
Selects "second update" (once per second) as the timing for generation of
0
interrupt events
Selects "minute update" (once per minute) as the timing for generation of
1
interrupt events
Data
The UF bit is cleared to zero to prepare for the next status detection
0
Clearing this bit to zero does not enable the /INT low output status to be cleared (to Hi-Z).
1
Invalid (writing a 1 will be ignored)!
0
Time update interrupt events are not detected.
Time update interrupt events are detected.
1
(The result is retained until this bit is cleared to zero.)
Data
1) Does not generate an interrupt signal when a time update interrupt event
occurs (/INT remains Hi-Z)
2) Cancels interrupt signal triggered by time update interrupt event (/INT
0
changes from low to Hi-Z).
Even when the UIE bit value is "0" another interrupt event may change the /INT status to low (or
may hold /INT =L).
When a time update interrupt event occurs, an interrupt signal is generated
(/INT status changes from Hi-Z to low).
1
When a time update interrupt event occurs, low-level output from the /INT pin occurs only when the
UIE bit value is "1". Earliest 7.813ms after the interrupt occurs, the /INT status is automatically
cleared (/INT status changes from low to Hi-Z).
Page - 26
bit 5
bit 4
bit 3
TE
FSEL1
UF
TF
AF
UIE
TIE
AIE
Description
Description
Description
bit 2
bit 1
bit 0
FSEL0
TSEL1
TSEL0
VLF
VDET
RESET
ETM60E-02
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