wm9081 Wolfson Microelectronics plc, wm9081 Datasheet - Page 75

• Manufacturer Part Number: wm9081
• Description: Mono Dac With 2.6w Class Ab/d Speaker Driver, Dynamic Range Controller And Retune Mobile Parametric Equalizer
• Manufacturer: Wolfson Microelectronics plc

Pre-Production
INTERRUPTS
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The interrupt controller has two inputs; these are the Temperature Sensor and the Control Write
Sequencer. Any combination of these inputs can be used to trigger an Interrupt (IRQ) event.
There is an Interrupt Status field associated with each of the IRQ inputs. These are listed within the
Interrupt Status Register, R26 (1Ah), as described in Table 45. The status of the IRQ inputs can be
read at any time from this register or else in response to the interrupt event being signalled via the
IRQ
Individual mask bits can select or deselect different functions from the Interrupt controller. These are
listed within the Interrupt Status Mask Register, R27 (1Bh), as described in Table 45. Note that the
status fields remain valid, even when masked, but the masked bits will not cause the IRQ
asserted.
The interrupt output represents the logical ‘OR’ of all the unmasked IRQ inputs. Each bit within the
Interrupt Status register R26 (1Ah) is a latching bit - once it is set, it remains at logic 1 even if the
trigger condition is cleared. The interrupt status bits are cleared by writing a logic 1 to the relevant
register bit. Accordingly, the IRQ
reset.
When the temperature sensor is used as an interrupt event, the polarity can be set using
TSHUT_INV. This allows the IRQ event to be used to indicate either the normal temperature
condition or the over-temperature condition. Under default conditions (TSHUT_INV = 0), the interrupt
will be triggered in response to an over-temperature condition.
By default, the IRQ
output may be configured as either CMOS or Open-Drain type. In Open Drain mode, a logic 1 is
asserted by tri-stating the IRQ
to pull the IRQ
The WM9081 Interrupt Controller circuit is illustrated in Figure 54. The associated control fields are
described in Table 45. Note that CLK_SYS is required for the interrupt circuit.
Figure 54 Interrupt Controller
¯ ¯ ¯ pin.
¯ ¯ ¯ high so that the logic 1 can be recognised by another device.
¯ ¯ ¯ output is Active Low. The polarity can be inverted using IRQ_POL. The IRQ
¯ ¯ ¯ pin, rather than pulling it high. An external pull-up resistor is required
¯ ¯ ¯ output is not reset until each of the unmasked IRQ inputs has been
PP, Rev 3.0, April 2009
WM9081
¯ ¯ ¯ to be
¯ ¯ ¯
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