SCPS065D

The Texas Instruments PCI1520, a 208-terminal dual-slot CardBus controller designed to meet the PCI Bus Power Management Interface Specification for PCI to CardBus Bridges, is an ultralow-power high-performance PCI-to-CardBus controller that supports two independent card sockets compliant with the PC Card Standard (rev. 7.1). The PCI1520 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 PCI Local Bus Specification and defines the new 32-bit PC Card, CardBus, capable of full 32-bit data transfers at 33 MHz. The PCI1520 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 PCI1520 is compliant with the PCI Local Bus Specification, and its PCI interface can act as either a PCI master device or a PCI slave device. The PCI bus mastering is initiated during CardBus PC Card bridging transactions. The PCI1520 is also compliant with PCI Bus Power Management Interface Specification (rev. 1.1). All card signals are internally buffered to allow hot insertion and removal without external buffering. The PCI1520 is register-compatible with the Intel 82365SL-DF and 82365SL ExCA controllers. The PCI1520 internal data path logic allows the host to access 8-, 16-, and 32-bit cards using full 32-bit PCI cycles for maximum performance. Independent buffering and a pipeline architecture provide an unsurpassed performance level with sustained bursting. The

PCI1520 can also be programmed to accept fast posted writes to improve system-bus utilization. Multiple system-interrupt signaling options are provided, including parallel PCI, parallel ISA, serialized ISA, and serialized PCI. Furthermore, general-purpose inputs and outputs are provided for the board designer to implement sideband functions. Many other features designed into the PCI1520, such as socket activity light-emitting diode (LED) outputs, are discussed in detail throughout the design specification.

An advanced complementary metal-oxide semiconductor (CMOS) process achieves low system power consumption while operating at PCI clock rates up to 33 MHz. Several low-power modes enable the host power management system to further reduce power consumption.