Datasheet

Functional Description

Intel® Xeon® Processor D-1500 Product Family 77

Datasheet - Volume 1 of 4: Integrated Platform Controller Hub

March 2015

3.8 8259 Programmable Interrupt Controllers (PIC)

(D31:F0)

Intel® Xeon® Processor D-1500 Product Family incorporates the functionality of two

8259 interrupt controllers that provide system interrupts for the ISA compatible

interrupts. These interrupts can include: system timer, keyboard controller, serial ports,

parallel ports, floppy disk, mouse, and DMA channels. In addition, this interrupt

controller can support the PCI based interrupts, by mapping the PCI interrupt onto the

compatible ISA interrupt line. Each 8259 controller supports eight interrupts, numbered

0–7. Ta b l e 3- 1 3 shows how the controllers are connected.

Intel® Xeon® Processor D-1500 Product Family cascades the slave controller onto the

master controller through master controller interrupt input 2. This means there are

only 15 possible interrupts for Intel® Xeon® Processor D-1500 Product Family PIC.

Interrupts can individually be programmed to be edge or level, except for IRQ0, IRQ2,

IRQ8#, and IRQ13.

Note: Active-low interrupt sources (such as, the PIRQ#s) are inverted inside Intel® Xeon®

Processor D-1500 Product Family. In the following descriptions of the 8259s, the

interrupt levels are in reference to the signals at the internal interface of the 8259s,

after the required inversions have occurred. Therefore, the term “high” indicates

“active,” which means “low” on an originating PIRQ#.

Table 3-13. Interrupt Controller Connections

8259

Input

Typical Interrupt

Source

Connected Pin / Function

Master 0 Internal Internal Timer / Counter 0 output / HPET #0

1 Keyboard IRQ1 using SERIRQ

2 Internal Slave controller INTR output

3 Serial Port A IRQ3 using SERIRQ,

4 Serial Port B IRQ4 using SERIRQ, PIRQ#

5 Parallel Port / Generic IRQ5 using SERIRQ, PIRQ#

6 Floppy Disk IRQ6 using SERIRQ, PIRQ#

7 Parallel Port / Generic IRQ7 using SERIRQ, PIRQ#

Slave 0 Internal Real Time Clock Internal RTC / HPET #1

1 Generic IRQ9 using SERIRQ, SCI, TCO, or PIRQ#

2 Generic IRQ10 using SERIRQ, SCI, TCO, or PIRQ#

3 Generic IRQ11 using SERIRQ, SCI, TCO, or PIRQ#, or HPET #2

4 PS/2 Mouse IRQ12 using SERIRQ, SCI, TCO, or PIRQ#, or HPET #3

5 Internal State Machine output based on processor FERR#

assertion. May optionally be used for SCI or TCO interrupt

if FERR# not needed.

6 SATA SATA Primary (legacy mode), or using SERIRQ or PIRQ#

7 SATA SATA Secondary (legacy mode) or using SERIRQ or PIRQ#