Epson RX8111CE, Applications Manual, Page: 36 / 67

RX8111CE
Page
−
32 ETM61E-01
14.4. Time Update Interrupt Function
The time update interrupt function generates interrupt in one-second or one-minute intervals which are synchronized to the update
of the second or minute time register of the RTC. When an interrupt event is generated, this /INT status is automatically cleared
(/INT status changes from low level to Hi-Z 7.57 ms after the interrupt occurs).
14.4.1. Related registers for time update interrupt functions.
Table 31 Time update interrupt register
Address Function bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0
1Dh Extension Register FSEL1 FSEL0 USEL TE WADA ETS TSEL1 TSEL0
1Eh Flag Register POR z UF TF AF EVF VLF XST
1Fh Control Register z z UIE TIE AIE EIE z STOP
Before entering settings for operations, it is recommended writing a "0" to the UIE bit to prevent hardware interrupts from occurring
inadvertently while entering settings.
When the STOP bit value is "1"
time 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.
Time update interrupt function cannot be inactive. User can set /INT output inactive.
1) USEL bit (Update Interrupt Select)
This bit is used to select "second" update or "minute" update as the timing for generation of time update interrupt events.
Table 32 USEL bit (Update Interrupt Select)
USEL data Description
Write / Read
0
Selects "second update" (once per second) as the timing for generation of interrupt
events
1
Selects "minute update" (once per minute) as the timing for generation of interrupt
events
2) UF bit (Update Flag)
This flag bit value changes from "0" to "1" when a time update interrupt event occurs.
Table 33 UF bit (Update Flag)
UF data Description
Write
0
Clearing this bit to zero enables /INT low output to be canceled (/INT
remains Hi-Z) when a time update interrupt event has occurred
.
1 Invalid
．
Read
0
−
1
Time update interrupt events are detected.
(The result is retained until this bit is cleared to zero.)
3) UIE bit (Update Interrupt Enable)
This bit selects whether to generate an interrupt signal or to not generate it.
Table 34 UIE bit (Update Interrupt Enable)
UIE data Description
Write / Read
0
1) Does not output an interrupt signal when a time update interrupt event occurs.
2) interrupt output of only time update event is cancelled.
1
When a time update interrupt event occurs, an interrupt signal is generated (/INT
status changes from Hi-Z to low).
Earliest 7.57 ms after the interrupt occurs, the /INT is released automatically (/INT
status changes from low to Hi-Z).