wm9712l Wolfson Microelectronics plc, wm9712l Datasheet - Page 50

• Manufacturer Part Number: wm9712l
• Description: Ac?97 Audio And Touchpanel Codec
• Manufacturer: Wolfson Microelectronics plc

WM9712L
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COMP2 DELAY FUNCTION
COMP2 has an optional delay function for use when the input signal is noisy. When COMP2 triggers
and the delay is enabled (i.e. COMP2DEL is non-zero), then GPIO bit 14 does not change state
immediately, and no interrupt is generated. Instead, the WM9712L starts a delay timer and checks
COMP2 again after the delay time has passed. If COMP2 is still active, then the GPIO bit is set and
an interrupt may be generated (depending on the state of the GW14 bit). If COMP2 is no longer
active, the GPIO bit is not set, i.e. all register bits are as if COMP2 had never triggered.
Note: If COMP2 triggers while the WM9712L is in sleep mode, and the delay is enabled, then the
device starts the on-chip crystal oscillator in order to count the time delay.
Figure 14 COMP2 Delay Flow Chart
000
time=COMP2DEL
START TIMER
SHUT DOWN
TRIGGERS
SET GI14
COMP2?
non-zero
COMP2
COMP2
TIMER
C2W?
Active
WAIT
DEL?
END
1
Inactive
0
[FALSE ALARM]
END
END
PD Rev 4.5 August 2006
Production Data
50