S-35740C01A-K8T2U Datasheet, PDF (14/31 Pages) Seiko Instruments Inc – Operation temperature range

FOR AUTOMOTIVE 125°C OPERATION 2-WIRE INTERVAL TIMER CONVENIENCE TIMER
S-35740 Series
Rev.1.1_00
 Timer
The S-35740 Series has a built-in 24-bit timer. The timer performs a count-up action every second and stops at
"FFFFFF h". Even if the timer stops, the clock pulse output of INT pin is not affected.
Input a timer reset command to the S-35740 Series in order to reset the timer. Thereby, the timer restarts the operation.
Refer to "Figure 21 Acknowledge Output Timing" and "Figure 22 Data Transmission Format of Serial Interface"
regarding the timer reset command.
As shown in "Figure 13 INT Pin Output Timing Example 1 (Nch Open-drain Output)" and "Figure 15 INT Pin
Output Timing Example 2 (Nch Open-drain Output)", the S-35740 Series resets the internal signal when the write
operation of the fixed-cycle interrpt signal setting register is performed. The internal signal generates a count-up signal of
the timer every second. Therefore, the count-up action of the timer will be delayed for up to 1 second when the write
operation of the fixed-cycle interrupt signal setting register is performed. Figure 17 shows the operation outline.
ɾWhen ENBL pin does not change or write operation of fixed-cycleinterrput signal setting register is not performed
1 Hz
Timer
(n 1) seconds
1 second
(n) seconds
1 second
(n 1) seconds
1 second
ɾWhen ENBL pin changes
Change of ENBL pin
1 Hz
Timer
(n 1) seconds
1 second
(n) seconds
1 second
ɾWhen write operation of fixed-cycle interrput signal setting register is performed (at ENBL pin = "H" )
(n 1) seconds
1 second
Delay of
timer count-up action
Write operation of fixed-cycle
interrput signal setting register
1 Hz
Timer
(n 1) seconds
Internal signal
reset
(n) second
1 second
1 second
Figure 17 Timer Count-up Action and Internal Signal Reset
(n 1) seconds
1 second
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