PATH ADC Home > Documentation > Hardware > Device Managers and Drivers > PCI Card Services > Designing PCI Cards and Drivers for Power Macintosh Computers

ExpMgrIOReadLong

You can use the ExpMgrIOReadLong function to read the long word value at a specific address in PCI I/O space.



 
OSErr ExpMgrIOReadLong (

                     RegEntryIDPtr node,

                     LogicalAddress ioAddr,

                     UInt32 *valuePtr);

node: A node identifier that identifies a device node. If you specify a node identifier that isn't in the device tree, ExpMgrIOReadLong returns a result code of deviceTreeInvalidNodeErr.
ioAddr: The sum of the assigned-addresses base address of the device plus the offset to the desired I/O address.
valuePtr: The returned 32-bit value as it would appear on the PCI bus. The function performs the necessary byte swapping.

DESCRIPTION

The ExpMgrIOReadLong function reads the long word starting at the I/O address for device node node determined by address ioAddr, returning its byte-swapped value in valuePtr.

RESULT CODES

`noErr`	0	No error
`deviceTreeInvalidNodeErr`	-2538	Device node not in the device tree