The UM82C481BF is a high-performance Peripheral Component Interconnect (PCI) to Enhanced IDE (EIDE) bridge controller manufactured by UMC Corporation. It serves as a crucial interface between the PCI bus and EIDE devices, facilitating fast and efficient data transfer between the host system and storage devices such as hard drives and CD-ROM drives.

Applications

• Desktop Computers: Used to connect hard drives, CD-ROM drives, and other EIDE peripherals to the PCI bus.
• Embedded Systems: Integrated into embedded systems requiring high-speed storage interfaces.
• Industrial PCs: Employed in industrial PCs for reliable data storage and retrieval.
• Motherboards: Found on motherboards as a key component of the storage subsystem.

Features

• PCI Bus Compliance: Adheres to the PCI bus specification, ensuring compatibility with a wide range of PCI-based systems.
• EIDE Support: Supports EIDE devices, enabling connection to various storage devices.
• Bus Mastering: Implements bus mastering capabilities, allowing the device to directly transfer data to and from memory without CPU intervention, improving performance.
• PIO Mode Support: Supports PIO (Programmed Input/Output) modes for data transfer.
• DMA Support: Supports DMA (Direct Memory Access) for high-speed data transfer.

Benefits

• Improved Data Transfer Rates: Enables faster data transfer between the host system and EIDE devices.
• Enhanced System Performance: Reduces CPU overhead by using bus mastering and DMA capabilities.
• Increased Storage Capacity: Supports multiple EIDE devices, allowing for greater storage capacity.
• Wide Compatibility: Compatible with a broad range of PCI-based systems and EIDE devices.

Additional Details

The UM82C481BF typically operates at 33 MHz and supports both PIO and DMA modes. It is a single-chip solution that integrates all the necessary logic for interfacing between the PCI bus and EIDE devices. The device is designed for low power consumption and is available in a variety of packages. This chip was commonly found in older computer systems, bridging the gap between the then-modern PCI bus and the legacy EIDE storage interface. Its integration streamlined motherboard design and improved data throughput compared to previous solutions.