FDC37M81x SMSC Corporation, FDC37M81x Datasheet - Page 114

• Manufacturer Part Number: FDC37M81x
• Description: PC98/99 Compliant Enhanced Super I/O Controller
• Manufacturer: SMSC Corporation

The SER_IRQ data frame supports IRQ2 from a logical device on Period 3, which can also be used for
the System Management Interrupt (nSMI). When using Period 3 for IRQ2 the user should mask off the
SMI via the SMI Enable Register. Likewise, when using Period 3 for nSMI the user should not configure
any logical devices as using IRQ2.
SER_IRQ Period 14 is used to transfer IRQ13. Logical devices 0 (FDC), 3 (Par Port), 4 (Ser Port 1), 5
(Ser Port 2), and 7 (KBD) shall have IRQ13 as a choice for their primary interrupt.
The SMI is enabled onto the SMI frame of the Serial IRQ via bit 6 of SMI Enable Register 2.
SER_IRQ PERIOD
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
SIGNAL SAMPLED
SER_IRQ Sampling Periods
nSMI/IRQ2
Not Used
IRQ10
IRQ11
IRQ12
IRQ13
IRQ14
IRQ15
IRQ1
IRQ3
IRQ4
IRQ5
IRQ6
IRQ7
IRQ8
IRQ9
114
# OF CLOCKS PAST START
11
14
17
20
23
26
29
32
35
38
41
44
47
2
5
8