Specifications

AR-B1564 User¡¦s Guide
3-13
(A) CPU Clock Multiplier Select (SW1)
The CPU clock multiplier needs to be set by SW1.
SW1-1 SW1-2 SW1-3 P54C P55C
ON ON OFF 2.5X 2.5X
OFF ON OFF 3.0X 3.0X
ON OFF OFF 2.0X 2.0X
OFF OFF OFF 1.5X 3.5X
ON ON ON -- 4.5X
OFF ON ON -- 5.0X
ON OFF ON -- 4.0X
OFF OFF ON -- 5.5X
Table 3-6 SW1: CPU Clock Multiplier
(B) CPU Base Clock Select (SW1)
This board supports different types of CPUs. The clock generator needs to be set by SW1.
The CPU input clock is twice the operation clock.
SW1-4 SW1-5 SW1-6 Base Clock PCI Clock
ON ON OFF 50MHz 25MHz
OFF ON OFF 66.6MHz 33.3MHz
ON OFF OFF 60MHz 30MHz
OFF OFF OFF 55MHz 27.5MHz
ON ON ON 51.3MHz 25.6MHz
OFF ON ON 68.4MHz 34.2MHz
ON OFF ON 61.6MHz 30.8MHz
OFF OFF ON 75MHz 37.5MHz
Table 3-7 SW1: CPU Clock Multiplier
NOTE: 1. SW1 jumper setting – BF0-BF2: On presents Low, Off presents High.
2. Intel CPU MMX – 233 is factory default setting.
(3) P54C/P55C CPU Type Select (JP2)
Figure 3-21 JP2: P54C/P55C CPU Type Select