SM8578BV Nippon_Precision_Circuits America, SM8578BV Datasheet - Page 10

• Manufacturer Part Number: SM8578BV
• Description: Real-time Clock ic
• Manufacturer: Nippon_Precision_Circuits America

Timer interrupt
The timer interrupt mode (level interrupt or repetitive
interrupt) is selected by the setting of TI/TP. In timer
mode, AIE and FE should be set to 0.
Level interrupt mode (TI/TP = 0)
When TIE is 1 and a timer interrupt event occurs,
INTN goes LOW and TF is set to 1. INTN goes into
a high-impedance state when 0 is written to TF.
Repetitive interrupt mode (TI/TP = 1)
When TIE is 1 and a timer interrupt event occurs,
INTN goes LOW and TF is set to 1. INTN then goes
into a high-impedance state after the auto-return
The auto-return time (t
source clock frequency set by register address C as
shown in the following table.
INTN output
INTN output
TIE bit
TF bit
TIE bit
TF bit
RTN
) is determined by the
t
RTN
Data 0 written to TF
SM8578BV
Data 0 written to TF
When TIE is 0, however, INTN is in a high-imped-
ance state.
time. TF remains 1 until 0 is written to TF. When TIE
is 0, however, INTN is in a high-impedance state.
No output
while TIE is 0
S o u rce clock
4096 Hz
1/60 Hz
64 Hz
1 Hz
Auto-return
NIPPON PRECISION CIRCUITS—10
"1"
"0"
Hi-Z
LOW-level
"1"
"0"
Timer interrupt
timing
Timer interrupt
timing
"1"
"0"
Hi-Z
"1"
"0"
LOW-level
A uto-return time (t
0.122 ms
0.122 ms
7.81 ms
0.5 s
R T N
)