WM8900LGEFK/RV Wolfson Microelectronics, WM8900LGEFK/RV Datasheet - Page 60

• Manufacturer Part Number: WM8900LGEFK/RV
• Description: Audio CODECs Ultra Low Power Hi-Fi CODEC
• Manufacturer: Wolfson Microelectronics

Specifications of WM8900LGEFK/RV

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

WM8900
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Figure 23 Volume Update Using Zero Cross Detection
If there is a long period where no zero-crossing occurs, a timeout circuit in the WM8900 will
automatically update the volume. The volume updates will occur between one and two timeout
periods, depending on when the volume update bit is set as shown in Figure 24. The TOCLK_ENA
register bit must be set to enable this timeout function. The timeout period is set by TOCLK_RATE.
Figure 24 Volume Update after Timeout
Right PGA Output
Timeout Counter
Left PGA Output
Control Interface
Right PGA Input
Left PGA Input
Write Left PGA Volume
without update
Write Left
Volume
Update
bit = 0
Volume
Update
bit = 1
Write
Right
Write Right PGA Volume
with update
SYSCLK/2
No zero crossing
depending on TOCLK_RATE
Zero crossing causes
volume update
21
or SYSCLK/2
Timeout causes
volume update
19
,
PD, August 2008, Rev 4.0
Time
Production Data
60