wm9715l Wolfson Microelectronics plc, wm9715l Datasheet - Page 50

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

WM9715L
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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 the C2I bit in register 54h does not
change state immediately, and no interrupt is generated. Instead, the WM9715L starts a delay timer
and checks COMP2 again after the delay time has passed. If COMP2 is still active, then the interrupt
bit is set and an interrupt may be generated (depending on the state of the GW14 bit). If COMP2 is
no longer active, the interrupt bit is not set, i.e. all register bits are as if COMP2 had never triggered.
Note: If COMP2 triggers while the WM9715L 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 4.0 December 2007
Production Data
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