Texas Instruments Dual/Single Socket CardBus and UntraMedia Controller PCI7621 - Manual (Page 237)

10−7
10.5 Power-Class Programming
The PC0–PC2 terminals are programmed to set the default value of the power-class indicated in the pwr field
(bits 21–23) of the transmitted self-ID packet. Table 10−9 shows the descriptions of the various power classes. The
default power-class value is loaded following a system (hardware) reset, but is overridden by any value subsequently
loaded into the Pwr_Class field in register 4.
Table 10−9. Power Class Descriptions
PC0–PC2 DESCRIPTION
000 Node does not need power and does not repeat power.
001 Node is self-powered and provides a minimum of 15 W to the bus.
010 Node is self-powered and provides a minimum of 30 W to the bus.
011 Node is self-powered and provides a minimum of 45 W to the bus.
100 Node may be powered from the bus and is using up to 3 W. No additional power is needed to enable the link.
101 Reserved
110 Node is powered from the bus and uses up to 3 W. An additional 3 W is needed to enable the link.
111 Node is powered from the bus and uses up to 3 W. An additional 7 W is needed to enable the link.