GT-64260A Design Guide
Doc. No. MV-S300165-00, Rev. A
CONFIDENTIAL
Copyright © 2002 Marvell
Page 82
Document Classification: Proprietary Information
May 21, 2002, Preliminary
Section 11. Interrupt Controller Functional Overview
The GT-64260A can drive up to seven interrupt pins:
•
Interrupt* - dedicated interrupt output to CPU.
•
PCI_Int*0 - dedicated interrupt open-drain output to PCI0.
•
PCI_Int*1 - dedicated interrupt open-drain output to PCI1.
•
Int*[3:0] – four additional CPU interrupts multiplexed on MPP pins.
All seven interrupts driven by the GT-64260A are "Level Sensitive Type". The interrupt is kept active as long as
there is at least one non-masked cause bit set in the Interrupt Cause register.
If the interrupt source is an external device driving a GPP input (see
8.1 "General Purpose Pin (GPP)" on page
), the GT-64260A can be configured to receive a level or edge trigger. If the Comm Unit Arbiter Control register’s
GPP_Int
bit [10] is set to ‘0’, at offset 0xF300, the external interrupts are treated as edge trigger interrupts. This
means an assertion of a GPP input pin results in setting the corresponding bit in the GPP Interrupt Cause register.
Only an edge will trigger the interrupt.
If the
GPP_Int
bit is set to ‘1’, the external interrupts are treated as level interrupts. In this mode, an interrupt is
always generated as long as at least one of the GPP Value register bits is asserted and the GPP Interrupt Mask
register does not mask it.