EP80579 Datasheet, PDF (744/1916 Pages) Intel Corporation – Intel® EP80579 Integrated Processor Product Line

Intel^® EP80579 Integrated Processor
19.2.3.5 Offset 64h: SCNT: Serial IRQ Control Register
Table 19-18. Offset 64h: SCNT: Serial IRQ Control Register
Description:
View: PCI
BAR: Configuration
Bus:Device:Function: 0:31:0
Offset Start: 64h
Offset End: 64h
Size: 8 bit
Default: 10h
Power Well: Core
Bit Range
07
06
05 :02
01 :00
Bit Acronym
Bit Description
Sticky
EN
MD
FS
SFPW
Enable:
0 = Serial IRQs will not be recognized
1 = Serial IRQs are recognized
Mode:
0 = The serial IRQ machine is in quiet mode
1= The serial IRQ machine is in continuous mode
Note: For systems using Quiet Mode, this bit must be
set to 1 (Continuous Mode) for at least one frame
after coming out of reset before switching back to
Quiet Mode. Failure to do so will result in the IICH
not recognizing SERIRQ interrupts.
Frame Size:
100 = Hardwired to indicate the size of the SERIRQ frame
is 21 frames.
Start Frame Pulse Width: This is the number of 33 MHz
clocks that the SERIRQ pin is driven low by the Serial IRQ
controller to signal a start frame. In continuous mode, the
controller will drive the start frame for the number of
clocks specified. In quiet mode, the controller will drive
the start frame for the number of clocks specified minus
one, as the first clock was driven by the peripheral.
Bits Clocks
00 4
01 6
10 8
11 Reserved
Bit Reset
Value
0h
0h
0100b
00h
Bit Access
RW
RW
RO
RW
When exiting S3/S4/S5, the following procedure must be used if the system needs
Quiet Mode. Set the SERIRQ logic to continuous mode for at least one frame before
switching it back to Quiet Mode.
Intel^® EP80579 Integrated Processor Product Line Datasheet
744
August 2009
Order Number: 320066-003US