SMSC LAN9311 User Manual

Page of 460
Two Port 10/100 Managed Ethernet Switch with 16-Bit Non-PCI CPU Interface
Datasheet
SMSC LAN9311/LAN9311i
173
Revision 1.4 (08-19-08)
DATASHEET
 
14.2.1
Interrupts
This section details the interrupt related System CSR’s. These registers control, configure, and monitor
the IRQ interrupt output pin and the various LAN9311/LAN9311i interrupt sources. For more
information on the LAN9311/LAN9311i interrupts, refer to 
14.2.1.1
Interrupt Configuration Register (IRQ_CFG)
This read/write register configures and indicates the state of the IRQ signal.
Offset:
054h
Size:
32 bits
BITS
DESCRIPTION
TYPE
DEFAULT
31:24
Interrupt De-assertion Interval (INT_DEAS)
This field determines the Interrupt Request De-assertion Interval in multiples 
of 10 microseconds.
Setting this field to zero causes the device to disable the INT_DEAS Interval, 
reset the interval counter and issue any pending interrupts. If a new, non-
zero value is written to this field, any subsequent interrupts will obey the new 
setting.
This field does not apply to the PME_INT interrupt.
R/W
00h
23:15
RESERVED
RO
-
14
Interrupt De-assertion Interval Clear (INT_DEAS_CLR)
Writing a 1 to this register clears the de-assertion counter in the Interrupt 
Controller, thus causing a new de-assertion interval to begin (regardless of 
whether or not the Interrupt Controller is currently in an active de-assertion 
interval). 
0: Normal operation
1: Clear de-assertion counter
R/W
SC
0h
13
Interrupt De-assertion Status (INT_DEAS_STS)
When set, this bit indicates that interrupts are currently in a de-assertion 
interval, and will not be sent to the IRQ pin. When this bit is clear, interrupts 
are not currently in a de-assertion interval, and will be sent to the IRQ pin.
0: No interrupts in de-assertion interval
1: Interrupts in de-assertion interval
RO
SC
0b
12
Master Interrupt (IRQ_INT)
This read-only bit indicates the state of the internal IRQ line, regardless of 
the setting of the IRQ_EN bit, or the state of the interrupt de-assertion 
function. When this bit is set, one of the enabled interrupts is currently 
active.
0: No enabled interrupts active
1: One or more enabled interrupts active
RO
0b
11:9
RESERVED
RO
-
8
IRQ Enable (IRQ_EN)
This bit controls the final interrupt output to the IRQ pin. When clear, the IRQ 
output is disabled and permanently de-asserted. This bit has no effect on 
any internal interrupt status bits.
0: Disable output on IRQ pin
1: Enable output on IRQ pin
R/W
0b
7:5
RESERVED
RO
-