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PowerSpan II User Manual
80A1010_MA001_09
Integrated Device Technology
www.idt.com
7. Interrupt
Handling
An interrupt is a signal informing a program that an event (for example, an error) has occurred. When a
program receives an interrupt signal, it temporarily suspends normal processing and diverts the
execution of instructions to a sub-routine handled by an interrupt controller. The controller
communicates with the host processor and the device that initiated the interrupt to determine how to
handle the interrupt.
This chapter discusses the following topics about the PowerSpan II interrupt features:
•
“Interrupt Sources” on page 145
•
“Interrupt Registers” on page 147
•
•
•
7.1
Overview
PowerSpan II handles interrupts both from normal device operation and from exceptions. These
interrupts are programmed through certain register settings and are signaled through both input and
output signal pins.
The following sections describes PowerSpan II interrupt handling.
7.2
Interrupt Sources
Interrupt sources are classified as originating from normal device operation or conditions generated
from an exception.
These classifications are discussed in the following sections.
7.2.1
Interrupts from Normal Operations
Interrupt sources associated with normal device operations are:
•
Eight bidirectional, configurable interrupts pins:
P1_INTA#, P2_INTA#, INT[5:0]_
•
DMA channels (see
•
Doorbell interrupts (see
“Interrupt Enable Register 0” on page 332
for doorbell interrupt
generation)
•
Mailbox interrupts (see
“Mailbox x Register” on page 349
)