Chassis Support Component Configuration

After you add a CompactPCI chassis support component to your configuration, you can configure it by choosing the Settings node under the component. The following table shows the information you can use to configure each bridge device defined within the CompactPCI Chassis component.

Setting name Default setting Description
Slotpath Disabled Each string entered is a slot path that identifies the location of the cPCI slot in the chassis that is being configured. The slot path is constructed by concatenating slot numbers from the device to the slot number of PCI bus 0. Each slot number is in hexadecimal BIOS format. Shift the slot number by 3 to the left and use a bitwise-OR to combine the resulting number with the function number (slot << 3 bits to left | function).

For example, the slot path for a device identified at (2,12,0) [bus=2,device=12,function=0], with bus 2 as the secondary bus for the bridge at (0,17,0), will be 6088. The first slot number is 60h, corresponding to the device itself (slot 12, 0xC << 3 | 0). The second slot number is 88h, corresponding to its parent bridge (slot 17, 0x11 << 3 | 0).

Using slot number 12 as an example, follow these instructions:

  1. The slot number is converted into binary. 12 = 0000 1100.
  2. The binary number is shifted 3 bits to the left. 0000 1100 becomes 0110 0000.
  3. As your binary number is converted to hexadecimal, 0110 0000 becomes 60.
  4. The hexadecimal number is combined by a bitwise OR with the function number, 60 OR'ed with 0 = 60. This is the leaf.

In the same manner, the parent (17) is determined:

  1. The slot number is converted into binary, 11 = 0001 0001.
  2. The binary number is shifted 3 bits to the left; 0001 0001 becomes 1000 1000.
  3. The binary number is converted to hexadecimal; 1000 1000 becomes 88.
  4. The hexadecimal number is combined by a bitwise OR with the function number, 88 OR'ed with 0 = 88. This is the parent.

Finally, the parent is concatenated to the leaf. Therefore, the slot path for this example 6088.

Dynamic bus number assignment Disabled Overrides the sequential bus number assignment, which leaves no room for a new PCI bridge to be inserted, and allows dynamic bus numbering to occur instead.
Do not reset secondary bus Disabled Specifies that the OS does not reset the PCI bus segment when a failover occurs to another system slot board. This check box should be cleared for Windows XP Embedded because, by default, the OS does not reset the bus segment.
I/O space (From, To, Size) Disabled The From and To values specify the allowable range of I/O addresses for the PCI bridge device.

The Size value specifies the amount of I/O space within this range that the bridge is assigned.

Memory (From, To, Size) Disabled The From and To values specify the allowable range of memory addresses for the PCI bridge device.

The Size value specifies the amount of memory within this range that the bridge is assigned.

Prefetchable memory (From, To, Size) Disabled The From and To values specify the allowable range of prefetchable memory addresses for the PCI bridge device.

The Size value specifies the amount of prefetchable memory the bridge is allowed to use.

You can define resource assignments to any PCI bridge device regardless of its level. For example, you can define resource assignment for a PCI bridge device that is two levels down from Bus 0. The slot path value is used to describe where the PCI bridge exists.

If you type an asterisk (*) before a slot path string, the string refers to all the children of the PCI bridge as described by the slot path. For example, *68 refers to all child PCI bridges of the PCI bridge at slot path 68. Using this format, you can define resource assignments for all children of a PCI bridge. It is important to define these resource assignments because Windows XP Embedded distributes all available PCI resources to the devices that are present at boot time, and a PCI bridge device occupies all available resources. If you later insert a device using hot swap into a PCI bridge that contained a child PCI bridge, no resources are left to assign to that device because the child PCI bridge took the resources available for that slot path. By using the * format, you can limit the amount of resources that can be assigned to each child device, and reserve PCI resources for future devices that may be inserted using hot swap into the slot path.

See Also

CompactPCI | Generic CompactPCI Chassis Component

Last updated on Wednesday, October 18, 2006

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