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CP3002-RC/CP3002-RA
2.4
Timer
The CP3002-RC/CP3002-RA is equipped with the following timers:
• Real-Time Clock
The Intel® QM57 chipset integrates an MC146818B-compatible real-time clock with 256
Byte CMOS RAM. The CP3002-RC/CP3002-RA does not include a dedicated battery
power source for RTC backup. If the board is switched off, the RTC will lose its data. All
CMOS RAM data remain stored in an additional EEPROM device to prevent data loss.
The RTC can optionally be powered from an external voltage source via the rear I/O con-
nector J2 in order to retain the RTC data when the board is switched off.
• Counter/Timer
Three 8254-style counter/timers are included on the CP3002-RC/CP3002-RA as defined
for the PC/AT.
• The Intel® QM57 chipset integrates eight high-precision event timers.
2.5
Watchdog Timer
The CP3002-RC/CP3002-RA provides a Watchdog timer that is programmable for a timeout
period ranging from 125 ms to 4096 s in 16 steps. Failure to trigger the Watchdog timer in time
results in a system reset or an interrupt. In dual-stage mode, a combination of both interrupt
and reset if the Watchdog is not serviced. A hardware status flag will be provided to determine
if the Watchdog timer generated the reset.
2.6
Battery
The CP3002-RC/CP3002-RA does not include a dedicated battery power source for RTC
backup. If the board is switched off, the RTC will lose its data. All CMOS RAM data remain
stored in an additional EEPROM device to prevent data loss. The RTC can optionally be pow-
ered from an external voltage source via the rear I/O connector J2 in order to retain the RTC
data when the board is switched off.
2.7
Reset
The CP3002-RC/CP3002-RA is automatically reset by a precision voltage monitoring circuit
that detects a drop in voltage below the acceptable operating limit of 3.15 V for the 3.3 V line,
or in the event of a power failure of the DC/DC converters. Other reset sources include the
Watchdog timer. The CP3002-RC/CP3002-RA responds to any of these sources by initializing
local peripherals.
A reset will be generated if one the following events occurs:
• +3.3 V supply falls below 3.15 V (typ.)
• Power failure of at least one onboard DC/DC converter
• Watchdog expired
• CompactPCI backplane PRST input
ID 1039-3625, Rev. 1.0
Functional Description
Page 2 - 5
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