wm9715l Wolfson Microelectronics plc, wm9715l Datasheet - Page 51

• Manufacturer Part Number: wm9715l
• Description: Ac?97 Audio And Touchpanel Codec
• Manufacturer: Wolfson Microelectronics plc

Production Data
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INTERRUPT CONTROL
THE ADCIRQ PIN
THE PENDOWN PIN
THE GENIRQ PIN
The WM9715L has three interrupt pins:
•
•
•
In a typical use case with touchscreen measurements running continuously, “AUXADC data
available” is the most frequent type of interrupt event from the WM9715L. In the interest of
minimizing software overheads, it is recommended to use the dedicated ADCIRQ pin to transmit this
type of interrupt.
The ADCIRQ output is enabled using registers 56h and 4Ch.
Table 34 Enabling the ADCIRQ pin
In a typical use case, PENDOWN is the second most frequent type of interrupt after ADCIRQ. In the
interest of minimizing software overheads, it is recommended to use the dedicated PENDOWN pin to
transmit this type of interrupt.
The PENDOWN output is enabled using registers 56h and 4Ch.
Table 35 Enabling the PENDOWN pin
The GENIRQ pin transmits a logical OR of up to five individual interrupt events:
•
•
•
•
•
When the host processor receives an interrupt, it needs to read register 54h in order to determine
which event triggered the interrupt. As a result, GENIRQ is best suited for interrupts that occur rarely,
and where longer response times can be tolerated. ADCIRQ or PENDOWN interrupts should only be
4Ch
56h
4Ch
56h
REGISTER
REGISTER
ADDRESS
ADDRESS
ADCIRQ is a dedicated interrupt pin to indicate that AUXADC data is available for reading
(see “Touchpanel interface”)
PENDOWN is a dedicated interrupt pin to indicate that the resistive touchpanel
connected to the WM9715L is being touched (see “Touchpanel interface”)
GENIRQ is a general-purpose interrupt pin, which can indicate a number of different
events.
Over-temperature (see “Thermal Sensor”)
COMP1 events, e.g. dead battery alarm (see “Battery Alarm and Analogue Comparators”)
COMP2 events, e.g. low battery alarm (see “Battery Alarm and Analogue Comparators”)
ADCIRQ
PENDOWN
4
4
3
3
BIT
BIT
LABEL
LABEL
GC4
GE4
GC3
GE3
1
1
1
1
DEFAULT
DEFAULT
ADCIRQ output enable
ADCIRQ is enabled when both GC4 and GE4 are
To disable ADCIRQ, set both bits to ‘1’.
Other combinations (0/1, 1/0) are reserved.
PENDOWN output enable
PENDOWN is enabled when both GC4 and GE4 are
To disable PENDOWN, set both bits to ‘1’.
Other combinations (0/1, 1/0) are reserved.
set to ‘0’.
set to ‘0’.
DESCRIPTION
DESCRIPTION
PD Rev 4.0 December 2007
WM9715L
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