This section describes how drivers for PCMCIA devices in Microsoft Windows 2000 and later operating systems can access the attribute memory of a PCMCIA device:
- Requirements for Accessing Attribute Memory of a PCMCIA Device 
- Access PCMCIA Attribute Memory by Using a Plug and Play I/O Request - This is a simple method that is sufficient for most purposes, but can only run at IRQL < DISPATCH_LEVEL. 
- Access PCMCIA Attribute Memory by Using a BUS_INTERFACE_STANDARD Interface - This method eliminates the overhead of an I/O request and can run at IRQL <= DISPATCH_LEVEL 
- Access PCMCIA Attribute Memory Through a Permanent Memory Window - A driver's ISR can use this method to directly access memory while running at IRQL DIRQL. 
- Access PCMCIA Attribute Memory by Using a PCMCIA_INTERFACE_STANDARD Interface - Memory card drivers can use this method at IRQL <= DISPATCH_LEVEL. 
These methods are supported by pcmcia.sys, the system driver for a PCMCIA bus in Windows 2000 and later operating systems.