LAN9312 Datasheet, PDF (172/458 Pages) SMSC Corporation – High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface

14.2.1
14.2.1.1
High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface
Datasheet
Interrupts
This section details the interrupt related System CSR’s. These registers control, configure, and monitor
the IRQ interrupt output pin and the various LAN9312 interrupt sources. For more information on the
LAN9312 interrupts, refer to Chapter 5, "System Interrupts," on page 49.
Interrupt Configuration Register (IRQ_CFG)
Offset:
054h
Size:
32 bits
This read/write register configures and indicates the state of the IRQ signal.
BITS
DESCRIPTION
31:24
23:15
14
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.
RESERVED
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
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
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
11:9 RESERVED
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
7:5 RESERVED
TYPE
R/W
RO
R/W
SC
RO
SC
RO
RO
R/W
RO
DEFAULT
00h
-
0h
0b
0b
-
0b
-
Revision 1.2 (04-08-08)
172
DATASHEET
SMSC LAN9312