User manual

Chapter 6 System Configuration

Multiframe RM Operation

On power-up, all MXIbus devices are isolated from each other because

all address mapping windows are disabled. The multiframe RM

performs the following:

• Identifies all devices in the system

• Manages system self-tests

• Configures and enables the address map windows for logical

addresses, A16, A24, and A32

• Establishes initial Commander/Servant system hierarchy

• Initiates normal system operation

Configuring the Logical Address Window

To identify all devices in the VXIbus/MXIbus system, the RM

performs the following steps, starting where the RM is located.

1. If the multiframe RM resides in a PC, it scans all logical addresses

from 1 to FE (the RM is at address 0) to find all devices. For each

logical address, it reads the VXIbus ID Register (located at offset 0

within the device’s configuration space). If the read is successful

(that is, no BERR), a device is present at that logical address. If the

read returns a BERR, no device is present at that logical address.

The RM records all logical addresses found. For each VXI-MXI-2

found, it performs Step 2.

If the multiframe RM is in a VXIbus mainframe, it performs Step 2

for the mainframe in which the RM is installed.

2. For the current mainframe, the RM does the following:

A. Scans all logical addresses (0 to FF) in the mainframe to find

all static configuration (SC) and dynamic configuration (DC)

devices, skipping over logical addresses occupied by

previously encountered devices. Finds the Slot 0 device and

uses it to move all DC devices in the mainframe to the lowest

unused logical addresses. Records all logical addresses found

and allocated.