Intel C2518 FH8065501516710 Ficha De Dados
Códigos do produto
FH8065501516710
Volume 2—Serial Interrupt Controller—C2000 Product Family
Architectural Overview
Intel
®
Atom™ Processor C2000 Product Family for Microserver
Datasheet, Vol. 2 of 3
September 2014
494
Order Number: 330061-002US
23.2.2
Start Frame
The serialized IRQ protocol has two modes of operation which affect the start frame:
• Continuous Mode - The interrupt controller solely generates the start frame.
• Quiet Mode - The peripheral initiates the start frame, and the interrupt controller
• Quiet Mode - The peripheral initiates the start frame, and the interrupt controller
completes it.
23.2.2.1
Continuous Mode and Quiet Mode
These modes are programmed during the stop frame period discussed later in the
chapter. The continuous mode must be entered first, to start the first frame. The start
frame duration is eight LPC clock periods. This is considered an interrupt polling mode.
In quiet mode, the
line remains inactive (the signal floats) and is pulled-
up between the stop frame and start frame until a peripheral drives
low.
The SoC serialized interrupt controller senses the line low and drives it low for the
remainder of the start frame. Since the first LPC clock of the start frame was driven by
the peripheral, the interrupt controller drives
low for 1 LPC clock less than
in the continuous mode. This mode of operation allows for lower-power operation.
Note:
Refer to the Intel
®
Atom™ Processor C2000 Product Family BIOS Writer’s Guide
(BWG), Volume 2 of 2 - Section 12.2 and 12.3 for additional IRQ programming details.