Texas Instruments PCI-1251B CardBus Controller: The TI PCI1251B is a high-performance PC Card controller with a 32-bit PCI interface. The device supports two independent PC Card sockets compliant with the 1997 PC Card Standard. The PCI1251B provides features that make it the best choice for bridging between PCI and PC Cards in both notebook and desktop computers. The 1997 PC Card Standard retains the 16-bit PC Card specification defined in PCMCIA Release 2.2, and defines the new 32-bit PC Card, CardBus, capable of full 32-bit data transfers at 33 MHz. The PCI1251B supports any combination of 16-bit and CardBus PC Cards in the two sockets, powered at 5 V or 3.3 V, as required.The PCI1251B is compliant with the latest PCI Bus Power Management Specification. It is also compliant with the PCI Local Bus Specification 2.2, and its PCI interface can act as either a PCI master device or a PCI slave device. The PCI bus mastering is initiated during 16-bit PC Card direct memory access (DMA) transfers or CardBus PC Card bridging transactions.