Intel Desktop Board DQ45CB Technical Product Specification
24
1.7
Real-Time Clock Subsystem
A coin-cell battery (CR2032) powers the real-time clock and CMOS memory. When
the computer is not plugged into a wall socket, the battery has an estimated life of
three years. When the computer is plugged in, the standby current from the power
supply extends the life of the battery. The clock is accurate to
±
13 minutes/year at
25 ºC with 3.3 VSB applied.
NOTE
If the battery and AC power fail, custom defaults, if previously saved, will be loaded
into CMOS RAM at power-on. If the battery is removed or exhausted, the Intel TPM
data will be deleted in accordance to Trusted Computing Group guidelines. Please read
the user guide and back-up Intel TPM keys and data before removing the coin-cell
battery.
When the voltage drops below a certain level, the BIOS Setup program settings stored
in CMOS RAM (for example, the date and time) might not be accurate. Replace the
battery with an equivalent one. Figure 1 on page 11 shows the location of the battery.
