3–2
AlphaPC 164UX Jumper Configuration
CPU Speed Selection (Option 1,2,3, &4)
Figure 3–1 AlphaPC 164UX Configuration Jumpers
3.1 CPU Speed Selection (Option 1,2,3, &4)
The clock synthesizer makes it possible to change the frequency of the microproces-
sor’s clock input without having to change the clock crystal. Simply set the speed
jumpers to adjust the frequency of the microprocessor’s clock. These speed jumpers
are located at J28-1/2 (Option 1), J28-3/4 (Option 2), J28-5/6 (Option 3), and J28-7/8
(Option 4). These four jumpers set speed at power-up as listed in Figure 3–1.
J28 System Configuration Jumpers
Option 5 : Pyxis Bus Speed Select(Default Out)
Option 6 : Reserved Default Out
Option 7 : Enable SROM Debug Mode(Default Out)
Option 8 : Enable Firmware Debug Mode(Default Out)
Option 9 : Enable only 1 set of Scache(Default Out)
Option 10 : Reserved Default Out
Option 11 : Boot SAFE ARCSBIOS Image(Default Out)
Option 12 : Reserved Default Out
Option 13 : Must be In
Frequency
300 MHz
In
In
In
In
In
In
In
Out
In
In
333 MHz
366 MHz
Out
In
Bcache Size
In
In
Out
Out
Option14 Option15
0MB
1MB
2MB
4MB
Out
In
Out
In
400 MHz
Out
Out
In
In
In
Out
In
In
Out
In
433 MHz
466 MHz
In
Out
500 MHz
In
Out
Out
In
Out
Out
In
In
In
Out
533 MHz
566 MHz
Out
In
600 MHz
Out
In
In
Out
Out
In
Out
Out
In
Out
633 MHz
666 MHz
In
Out
700 MHz
In
In
Out
Out
In
Out
Out
Out
Out
Out
733 MHz
766 MHz
Out
In
800 MHz
Out
Out
Out
Out
Option 1
Option 2
Option 3
Option 4
Option 5
Option 6
Option 7
Option 8
Option 9
Option 10
Option 11
Option 12
Option 13
Option 14
Option 15
Option 16
Option1 Option2 Option3 Option4
Option 16 : FAN OK Signal Do not ever populate
(Default Out)
