le79128 Zarlink Semiconductor, le79128 Datasheet - Page 45

• Manufacturer Part Number: le79128
• Description: Next Generation Voiceedge™ Control Processor Next Generation Carrier Chipset Ngcc
• Manufacturer: Zarlink Semiconductor

Le79128
Preliminary Data Sheet
THE VCP DEVICE INTERRUPT REPORT AND SERVICE MECHANISM
There are two types of interrupt generated in the VCP device: the System Interrupt and the Event Interrupt.
The System Interrupts are hardware implemented and are maskable. Multiple System Interrupt sources may be reported
simultaneously.
The Event Interrupts are defined by the application and are reported one at a time. Three Event queues allow these interrupts to
be spooled off in the order they were received, per priority level.
An interrupt is normally reported to the host whenever there is any outstanding interrupt in the System Interrupt Source register
or one of the event queue interrupt fifo. An "event_delay" bit exists so that the lowest 2 event queues will not assert an interrupt
until a system or queue one interrupt occurs. This second option reduces the number of interrupts received by the host processor
to only the number of higher priority events. Interrupt to the external host is level sensitive. The INT pin remains High if there is
no pending interrupt. When an interrupt occurs, the INT pin is pulled Low to signal the external microcontroller that an interrupt
has occurred. Reading the interrupt indication register by the external microcontroller clears the interrupt. After reading the
interrupt indication register by the external microcontroller, the INT pin will go High if there is no pending interrupt. The INT pin
will continuously stay Low if there is another pending interrupt.
Interrupts are reported based on their priority. System interrupts have the highest priority. For the event interrupts, event queue
1 has the highest priority and event queue 3 has the lowest priority. The interrupt signal is latched before reporting to the host
through the INT pin.
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Microsemi Corporation - CMPG