The 82378ZB System I/O (SIO) and 82379AB System I/O APIC (SIO.A) components are PCI-to-ISA Bus Bridge devices. These devices integrate many of the common I/O functions found in todays ISA-based PC systems-a seven channel DMA controller, two 82C59 interrupt controllers, an 8254 timer/counter, a BIOS timer, Intel SMM power management support, and logic for NMI generation. In addition, the SIO and SIO.A each support a total of six PCI Masters, and four PCI Interrupts. Decode is provided for peripheral devices such as the flash BIOS, real time clock, keyboard/mouse controller, floppy controller, two serial ports, one parallel port, and IDE hard disk drive.

■ Provides the Bridge Between the PCI Bus and ISA Bus
■ 100% PCI and ISA Compatible
    - PCI and ISA Master/Slave Interface
    - Directly Drives 10 PCI Loads and 6 ISA Slots
    - PCI at 25 MHz and 33 MHz
    - ISA from 6 MHz to 8.33 MHz
■ Enhanced DMA Functions
    - Scatter/Gather (S/G) (82378ZB)
    - Fast DMA Type A, B and F (82378ZB)
    - Compatible DMA Transfers
    - 32-bit Addressability(82378ZB)
    - 27-bit Addressability(82379AB)
    - Seven Independently Programmable Channels
    - Functionality of Two 82C37A DMA Controllers
■ Data Buffers to Improve Performance
    - 8-Byte DMA/ISA Master Line Buffer
    - 32-bit Posted Memory Write Buffer to ISA
■ Integrated 16-bit BIOS Timer
■ Non-Maskable Interrupts (NMI)
    - PCI System Errors
    - ISA Parity Errors
■ Arbitration for ISA Devices
    - ISA Masters
    - DMA and Refresh
■ Four Dedicated PCI Interrupts
    - Level Sensitive
    - Mapped to Any Unused Interrupt
■ Arbitration for PCI Devices
    - Six PCI Masters Supported
    - Fixed, Rotating, or a Combination
■ Utility Bus (X-Bus) Peripheral Support
    - Provides Chip Select Decode
    - Controls Lower X-Bus Data Byte Transceiver
■ Functionality of One 82C54 Timer
    - System Timer
    - Refresh Request
    - Speaker Tone Output
■ Functionality of Two 82C59 Interrupt Controllers
    - 14 Interrupts Supported
    - Edge/Level Selectable Interrupts
■ I/O APIC (Advanced Programmable Interrupt Controller (82379AB)
    - Support for Multi-Processor Systems
■ System Power Management (Intel SMM Support)
    - Programmable System Management Interrupt (SMI)-Hardware Events, Software Events, EXTSMI#
    - Programmable CPU Clock Control (STPCLK#)
    - Fast-On/Off Mode
■ 208-Pin QFP Package