wm8961 Wolfson Microelectronics plc, wm8961 Datasheet - Page 77

• Manufacturer Part Number: wm8961
• Description: Ultra-low Power Stereo Codec With 1w Stereo Class D Speaker Drivers And Ground Referenced Headphone Drivers
• Manufacturer: Wolfson Microelectronics plc

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WM8961
Table 58 Additional Clock Configuration Register
Table 59 DC Servo Clock Configuration
Table 60 Class D Clock Rate Configuration
ADC and DAC
R56 (38h) Clocking 4
REGISTER
ADDRESS
Control 1
R5 (05h)
R8 (08h) Clocking2
REGISTER
ADDRESS
REGISTER
ADDRESS
BIT
2:1
8:5
BIT
ADDITIONAL SAMPLE RATE CONFIGURATION REQUIREMENTS
The DEEMPH[1:0], R5[2:1], should be configured to match the chosen DAC sample rate.
DC SERVO CLOCK
The DC Servo requires to be clocked at a nominal 1.536MHz. It is controlled by the CLK_DCS_CLK
configuration bits as shown in Table 59
CLASS D CLOCK
The Class D clock is divided from SYSCLK.
When SYSCLK is 12.288 MHz, the Class D clock operates at an optimum frequency of 384 kHz
When SYSCLK is 11.2896 MHz, the Class D clock operates at an optimum frequency of 352.8 kHz
It is controlled using the DCLKDIV[2:0] configuration bits. For optimal operation, DCLKDIV[2:0] should
be set to divide SYSCLK by 16, giving a clock of 768 KHz. This is further divided by 2 by the Class D
function which runs at 384 KHz
BIT
8:6
DEEMPH[1:0]
CLK_DCS_DIV[3:0]
LABEL
LABEL
DCLKDIV[2:0]
LABEL
DEFAULT
00
DEFAULT
1000
DEFAULT
111
DAC De-emphasis Filter Control
00: no de-emphasis
01: De-emphasis for 32kHz sample rate
10: De-emphasis for 44.1kHz sample rate
11: De-emphasis for 48kHz sample rate
Clock divider control for DC Servo, set to get 1.5Mhz
from SYSCLK
0000 : SYSCLK/1
0001 : SYSCLK/1.5
0010 : SYSCLK/2
0011 : Reserved
0100 : SYSCLK/3
0101 : SYSCLK/4
0110 : SYSCLK/5.5
0111 : SYSCLK/6
1000 : SYSCLK/8 (default for 12.288MHz/8 =
1.536MHz)
1001-1111 : Reserved
Divide of Class D clock from SYSCLK
000 : 1
001 : 2
010 : 3
011 : 4
100 : 6
101 : 8
110 : 12
111 : 16 (default for 12.288MHz/16 = 768
KHz)
(Note that Class D function further divides
by 2 to run at 384 KHz)
DESCRIPTION
DESCRIPTION
DESCRIPTION
PP, August 2009, Rev 3.1
Pre-Production
77