Timing Chart Of Evin Time Stamping; Int Pin Operation When An Interrupt Occurs - Epson RX8804CE Applications Manual

RX8804CE

8.4.2. Timing Chart of EVIN Time Stamping

EIE bit
/INT output
EF bit
Event
occurs
RTC internal operation
Write operation
Figure 11 EVIN Timing Chart
(1) An EVIN interrupt event occurred.
(2) At the same time, EF bit value becomes "1".
(3) When the EF bit = "1", its value is retained until it is cleared to zero.
(4) If EIE = "1" when an EVIN interrupt occurs, the /INT pin output goes low.
 When an EVIN interrupt event occurs, /INT pin output goes low, and this status is then held until it is cleared
via the EF bit or EIE bit.
(5) If the EIE value is changed from "1" to "0" while /INT is low, the /INT status immediately changes from low to
Hi-Z. After the EVIN interrupt occurs and during the EF bit value is 1, the /INT status can be controlled via the
EIE bit.
(6) If the EF bit value is changed from "1" to "0" while /INT is low, the /INT status immediately changes from low
to Hi-Z.
(7) If the EIE bit value is "0" when an EVIN interrupt occurs, the /INT pin status remains Hi-Z.

8.4.3. /INT pin Operation when an Interrupt Occurs.

1) How to identify events when the interrupt output occurs
/INT output pin is common output terminal of interrupt events of four types Wakeup timer, alarm, time update
and EVIN interrupt.
When an interrupt occurs, please read the TF, AF, UF and EF flag to confirm which types of events occurred.
2) Processing method in case of no using /INT output.
1. Please keep /INT pin open.
2. Please set "0" to TIE, AIE, UIE and EIE bits and do poling TF, AF, UF and EF.
" 1 "
(4)
(5)
(3)
(2)
(1)
Page - 20
(7)
(6)
" 1 "
" 0 "
Hi-Z
" L "
" 1 "
" 0 "
ETM59E-05