User`s manual

2
Board Jumpers and Connectors
The Alpha PCI 64–275 uses jumpers to implement variations in clock
frequency and L2 cache size and speed. These jumpers must be configured for
the user’s environment. Onboard connectors are provided for the I/O, memory
SIMMs, serial and parallel peripherals, integrated device electronics (IDE)
devices, and L2 cache SIMMs.
2.1 Configuration Jumpers
The software and hardware configuration jumpers are identified in Figures 2–1
and 2–2, and are described in Tables 2–1 and 2–2.
2.1.1 Software Configuration Jumpers
The software configuration jumpers are completely programmable. Each
jumper position is described in Table 2–1.
The SROM code defines the software configuration jumpers sp_bit<7:0>,as
shown in Figure 2–2 (see also Chapter 4).
The board ships with the jumpers listed in Tables 2–1 and 2–2 in the default
position.
Board Jumpers and Connectors 2–1