American Megatrends MAN-772 manual Configure CPU, External

Step 3 Configure CPU

Important

Perform the following steps to configure the

motherboard before installing a CPU.

External CPU Clock CLK1, CLK2, and CLK3 are 3-pin bergs that set the CPU external clock frequency. This motherboard may have any of four different clock generators:

∙IMI652,

∙ICS 9147,

∙ICW, or

∙PhaseLink.

The CLK1, CLK2, and CLK3 settings are different with the different clock generators. You must determine the clock generator type (it’s next to the CPU) before setting these jumpers.

IMI 652 Clock Generator The following CLK1, CLK2, and CLK3 settings apply only if an

IMI 652 clock generator is mounted on the motherboard.

External	CLK1	CLK2	FREQ1
(CPUCLK)
66 MHz	Short Pins 1-2	Short Pins 1-2	Short Pins 2-3
60 MHz	Short Pins 2-3	Short Pins 1-2	Short Pins 2-3
55 MHz	Short Pins 2-3	Short Pins 2-3	Short Pins 2-3
50 MHz	N/A	N/A	N/A

Cont’d

14Apollo IV PCI Pentium ISA Motherboard User’s Guide