OhcdPdd_CheckConfigPower

This function checks power for a requested configuration.

Syntax

BOOL OhcdPdd_CheckConfigPower( UCHAR bPort,
DWORD dwConfigPower, DWORD dwTotalPower );

Parameters

bPort

[IN] Specifies the root hub port number.

dwConfigPower

[IN] Specifies the power, in milliamps, required by the configuration being checked.

dwTotalPower

[IN] Specifies the power, in milliamps, drawn by other devices on this port.

Return Values

TRUE indicates that the USB system supports the configuration. FALSE indicates that a configuration is not supported.

Remarks

When a device is initially attached to the bus, OHC interface selects a configuration based on the power requirements of the system by calling this function for each configuration until one that is supported is found. If no configurations in a device are supported, the device is not configured.

This enables the platform to perform additional processing if necessary, such as checking whether the Windows CE–based platform is using batteries or external power, or possibly sampling the current system power status.

This function is declared in the Ohcdddsi.h header file.