Peripherals; Timer; Watchdog Timer; Battery - Kontron CP308 User Manual

CP308
2.2

Peripherals

The following standard peripherals are available on the CP308 board:
2.2.1

Timer

The CP308 is equipped with the following timers:
• Real-Time Clock
The ICH9M-SFF contains an MC146818A-compatible real-time clock, which performs
timekeeping functions and includes 256 bytes of general purpose battery-backed CMOS
RAM. Features include an alarm function, programmable periodic interrupt and a 100-
year calendar. All battery-backed CMOS RAM data remains stored in an additional EE-
PROM. This prevents data loss in case the CP308 is operated without battery.
• Counter/Timer
In addition to the three 8254-style counters, the ICH9M-SFF includes four individual high-
precision event timers (HPET) that may be used by the operating system. They are im-
plemented as a single counter each with its own comparator and value register.
2.2.2

Watchdog Timer

A user-configurable Watchdog timer with four different modes of operation is available. For
further information, refer to Chapter 4.3.12, Watchdog Timer Control Register.
2.2.3

Battery

The CP308 is provided with a 3.0 V "coin cell" lithium battery for the RTC.
Note ...
If an 8HP expansion module is used on the CP308, either the CP308 or the
expansion module may be equipped with a battery.
Using one battery on the CP308 and one on the expansion module simulta-
neously may result in premature discharge of the batteries.
To replace the battery, proceed as follows:
• Turn off power.
• Remove the battery.
• Place the new battery in the socket.
• Make sure that you insert the battery the right way round. The plus pole must be on the top!
The lithium battery must be replaced with an identical battery or a battery type recommended
by the manufacturer. A suitable battery type is CR2025.
Note ...
The user must be aware that the battery's operational temperature range is
less than the CP308's storage temperature range.
For exact range information, refer to the battery manufacturer's specifications.
ID 1027-4487, Rev. 3.0
Functional Description
Page 2 - 7