Datasheet

ACPI Devices
Intel
®
Atom™ Processor E6xx Series Datasheet
229
11.5.5 Serial Interrupts Not Supported
There are 4 interrupts on the serial stream which are not supported by the interrupt
controller. These interrupts are generated internally, and are not sharable with other
devices within the system. These interrupts are:
• IRQ0: Heartbeat interrupt generated off of the internal 8254 counter 0.
• IRQ8#: RTC interrupt can only be generated internally.
• IRQ13: This interrupt (floating point error) is not supported in the processor.
• IRQ14: PATA interrupt can only be generated from the external P-Device.
The interrupt controller will ignore the state of these interrupts in the stream.
11.5.6 Data Frame Format and Issues
Table 333 shows the format of the data frames. The decoded INT[A:D]# values are
ANDed with the corresponding PCI Express* input signals (PIRQ[A:D]#). This way, the
interrupt can be shared.
The other interrupts decoded via SERIRQ are also ANDed with the corresponding
internal interrupts. For example, if IRQ10 is set to be used as the SCI, then it is ANDed
with the decoded value for IRQ10 from the SERIRQ stream.
Table 333. Data Frame Format
Data
Frame #
Interrupt Clocks Past
Start Frame
Comment
1 IRQ0 2 Ignored. Can only be generated via the internal 8254
2 IRQ1 5 Before port 60h latch
3 SMI# 8 Causes SMI# if low. Sets bit 15 in the SMI_STS register
4IRQ3 11
5IRQ4 14
6IRQ5 17
7IRQ6 20
8IRQ7 23
9 IRQ8 26 Ignored. IRQ8# can only be generated internally
10 IRQ9 29
11 IRQ10 32
12 IRQ11 35
13 IRQ12 38 Before port 60h latch
14 IRQ13 41 Ignored.
15 IRQ14 44 Ignored
16 IRQ15 47
17 IOCHCK# 50 Same as ISA IOCHCK# going active.
18 PCI INTA# 53
19 PCI INTB# 56
20 PCI INTC# 59
21 PCI INTD# 62