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