Manual

Registers Format • 21

3.8 Interrupt Source Control (ISC) Register

The PCI-7396 has a dual interrupt system, two interrupt sources can be

generated and be distinguished by software setting. This register is used to

select the interrupt sources.

Address: BASE + 50h

Attribute: write only

Data Format:

Bit 7 6 5 4 3 2 1 0

BASE+50h x x x x C2_

C2_

C1_

BASE+51h x x x x x x x x

BASE+52h x x x x x x x x

BASE+54h x x x x x x x x

C1_0,C1_1 : Select source INT 1

C2_0,C2_1 : Select source INT 2

INT1 C1_1

C1_0

IRQ Sources IRQ Trigger Condition

Mode 1 0 0 COS P1&P2 (48bits) Change of State for PCI-

7396 P1 & P2

Mode 2 0 1 P1C0 OR ~P1C3 (see Table 4.2)

Mode 3 1 0 ~P1C0 falling edge of P1C0

Mode 4 1 1 Event Counter Counter count down to 0

INT2 C2_1

C2_0

IRQ Sources IRQ Trigger Condition

Mode 1 0 0 COS P3&P4(48bits) Change of State for PCI-

7396 P3 & P4

Mode 2 0 1 P2C0 OR ~P2C3 (see Table 4.2)

Mode 3 1 0 ~P2C0 falling edge of P2C0

Mode 4 1 1 32-bit Timer Timer count down to 0