cdp68hc68t1 Intersil Corporation, cdp68hc68t1 Datasheet - Page 20

• Manufacturer Part Number: cdp68hc68t1
• Description: Cmos Serial Real-time Clock With Ram And Power Sense/control
• Manufacturer: Intersil Corporation

System Diagrams
Example of an automotive system. The V
external switch is included to activate the system without turning on the ignition. Also, the CMOS CPU is not powered down
with the system V
will enable the CLK OUT pin and set the PSE and CPUR high.
Important Application Note: Those units with a code of 6PG have delayed alarm interrupts of 8.3ms regardless of
CDP68HC68T1’s operating frequency. (See "Functional Description", INT on page 10.) In addition, reading the Status
Register before delayed alarm activates will disable alarm signal.
12V
-
+
CLOCK BUTTON
REG
5V
DD
, but is held in a low power reset mode during power down. When restoring power the CDP68HC68T1
IGNITION
20
(Continued)
LINE
V
POR
XTAL
2MHz
BATT
V
V
T1
DD
SS
FIGURE 19. AUTOMOTIVE SYSTEM DIAGRAM
SYS
CLK OUT
CPUR
V
and LINE inputs can be used to sense the ignition turning on and off. An
PSE
SYS
INT
SPI
CE
CDP68HC68T1
3
ENABLED POWER
RESET
OSC1
IRQ
SPI
PORT
CDP68HC05C4B
V
V
DD
SS
PORT
October 29, 2007
FN1547.8