32579BCore Logic Module - ISA Legacy Register Space

 

 

Table 6-46. Programmable Interrupt Controller Registers

Bit

Description

 

 

 

 

I/O Port 020h / 0A0h

Master / Slave PIC ICW1 (WO)

 

 

7:5

Reserved. Must be set to 0.

 

 

4

Reserved. Must be set to 1.

 

 

 

3

Trigger Mode.

 

 

0: Edge.

 

 

1:

Level.

 

 

 

 

2

Vector Address Interval

 

 

0:

8 byte intervals.

 

 

1:

4 byte intervals.

 

 

 

1

Reserved. Must be set to 0 (cascade mode).

 

 

0

Reserved. Must be set to 1 (ICW4 must be programmed).

 

 

 

 

I/O Port 021h / 0A1h

Master / Slave PIC ICW2 (after ICW1 is written) (WO)

 

 

7:3

A[7:3]. Address lines [7:3] for base vector for interrupt controller.

 

 

2:0

Reserved. Must be set to 0.

 

 

 

 

I/O Port 021h / 0A1h

Master / Slave PIC ICW3 (after ICW2 is written) (WO)

 

 

Master PIC ICW3

 

 

 

7:0

Cascade IRQ. Must be 04h.

 

 

 

Slave PIC ICW3

 

 

 

 

7:0

Slave ID. Must be 02h.

 

 

 

 

 

I/O Port 021h / 0A1h

Master / Slave PIC ICW4 (after ICW3 is written) (WO)

 

 

7:5

Reserved. Must be set to 0.

 

 

4

Special Fully Nested Mode.

 

0:

Disable.

 

 

1:

Enable.

 

 

 

3:2

Reserved. Must be set to 0.

 

 

 

1

Auto EOI.

 

 

0: Normal EOI.

 

 

1:

Auto EOI.

 

 

 

0

Reserved. Must be set to 1 (8086/8088 mode).

 

 

 

 

I/O Port 021h / 0A1h (R/W)

Master / Slave PIC OCW1

 

 

 

(except immediately after ICW1 is written)

 

 

 

7

IRQ7 / IRQ15 Mask.

 

 

0: Not Masked.

 

 

1: Mask.

 

 

 

 

6

IRQ6 / IRQ14 Mask.

 

 

0: Not Masked.

 

 

1: Mask.

 

 

 

 

5

IRQ5 / IRQ13 Mask.

 

 

0: Not Masked.

 

 

1: Mask.

 

 

 

 

4

IRQ4 / IRQ12 Mask.

 

 

0: Not Masked.

 

 

1: Mask.

 

 

 

 

3

IRQ3 / IRQ11 Mask.

 

 

0: Not Masked.

 

 

1: Mask.

 

 

 

 

2

IRQ2 / IRQ10 Mask.

 

 

0: Not Masked.

 

 

1: Mask.

 

 

 

 

 

 

 

 

 

304

 

 

AMD Geode™ SC1200/SC1201 Processor Data Book

Page 304
Image 304
AMD SC1200, SC1201 manual Programmable Interrupt Controller Registers