DQ43AP Technical Product Specification

Intel Desktop Board DQ43AP Technical Product Specification
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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. Refer to the
TPM Quick Reference 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.
1.8 Legacy I/O Controller
The Legacy I/O controller provides the following features:
• One serial port header
• One parallel port back panel connector
• PS/2-style keyboard and mouse interfaces
• Serial IRQ interface compatible with serialized IRQ support for PCI systems
• Intelligent power management, including a programmable wake-up event interface
• PCI power management support
The BIOS Setup program provides configuration options for the I/O controller.
1.8.1 Serial Port
The board has one serial port header located on the component side of the board. The
serial port supports data transfers at speeds up to 115.2 kbits/sec with BIOS support.
For information about Refer to
The location of the serial port header Figure 10, page 44
The signal names of the serial port header Table 14, page 46