System Configuration and Connectors
2–5
CPU Speed Selection (Option 1,2,3, &4)
2.2 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 2–2.
2.3 Bcache Size Jumpers (Option 14,15)
The Bcache size jumpers are located at J28–27/28 (Option14) and J28–29/30
(Option15), as shown in Figure 2–2. The AlphaPC 164UX-2/-4 is configured with
2MB/4MB of Bcache during production ; the other jumpers shown in Figure 2–2
(0,1) are for other implementations.
Note:
The standard motherboard is manufactured with 128K
X
18 or 256K
X
18 data SSRAMs.
2.4 Boot Option Jumper (Option 11)
The boot option jumper is located at J28-21/22 (Option 11). The default position for
this jumper is out (Figure 2–2). This jumper selects the image to be loaded into mem-
ory from the system flash ROM. With the jumper out the ARCSBIOS firmware is
loaded. With the jumper in, the Safe ARCSBIOS is loaded.
2.5 AlphaPC 164UX Connector Pinouts
This section lists the pinouts of all AlphaPC 164UX connectors. See Figure 2–1 for
connector locations.
2.5.1 PCI Bus Connector Pinouts
Table 2–2 shows the PCI bus connector pinouts.
Table 2–2 PCI Bus Connector Pinouts
(Sheet 1 of 3)
Pin
Signal
Pin
Signal
Pin
Signal
Pin
Signal
32-Bit and 64-Bit PCI Connectors (J2, J5, J6, J7, J21, J22)
A1
TRST#
A2
+12V
A3
TMS
A4
TDI
A5
Vdd
A6
INTA
A7
INTC
A8
Vdd