NonStop S-Series Server Description Manual (G06.24+)

Principles of System Operation

HP NonStop S-Series Server Description Manual—520331-003

2-4

ServerNet Device Identification

When ServerNet devices communicate with each other, they provide a ServerNet

identification (ID) for both the target and the originator of the transmission. The format

of the ServerNet ID is shown in Figure 2-2.

For current purposes, the entire 20-bit value can be considered as an undivided

ServerNet ID. The reserved bits are not currently implemented. Also, the term

“ServerNet device” does not refer to I/O devices; as stated in the preceding topic, I/O

devices are never ServerNet devices.

In cases where multiple SACs interface with one SBI (see Figure 2-1), low-order bits in

the ServerNet ID can be used to distinguish each one as a “subdevice.” The example

in the upper part of Figure 2-2 shows two low-order bits being used as the ServerNet

subdevice field. The lower part of the figure shows how this encoding could be

interpreted for hardware references.