wm8953 Wolfson Microelectronics plc, wm8953 Datasheet - Page 74

• Manufacturer Part Number: wm8953
• Description: Low Power Stereo Adc With Pll And Tdm Interface Low Power Stereo Adc With Pll And Tdm Interface
• Manufacturer: Wolfson Microelectronics plc

WM8953
w
12
12
13
13
14.4
14.4
19.2
19.2
19.68
19.68
19.8
19.8
24
24
26
26
27
27
MCLK
(MHz)
11.2896
12.288
11.2896
12.288
11.2896
12.288
11.2896
12.288
11.2896
12.288
11.2896
12.288
11.2896
12.288
11.2896
12.288
11.2896
12.288
SYSCLK
(MHz)
EXAMPLE PLL CALCULATION
To generate 12.288MHz SYSCLK from a 12MHz reference clock:
There is a fixed divide by 4 at the PLL output (see Figure 50) followed by a selectable divide by 2 in
the same path. PLL output f
(MCLK_DIV = 10b) sets the required f
There is a selectable pre-scale (divide MCLK by 2) at the PLL input (f
frequency ratio f
sets the required ratio f
The required settings for this example are:
EXAMPLE PLL SETTINGS
Table 46 provides example PLL settings for generating common SYSCLK frequencies from a variety
of MCLK reference frequencies.
Table 46 PLL Frequency Examples
•
•
•
•
•
•
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
MCLK_DIV = 10b
PRESCALE = 0b
PLL_ENA = 1
SDM = 1
PLLN = 8 = 8h
PLLK = 0.192 = 3126h
MCLKDIV
2
/f
1
must be set in the range 5 - 13. Disabling the MCLK pre-scale (PRESCALE = 0b)
2
= SYSCLK * 4
/f
* MCLKDIV
90.3168
98.304
90.3168
98.304
90.3168
98.304
90.3168
98.304
90.3168
98.304
90.3168
98.304
90.3168
98.304
90.3168
98.304
90.3168
98.304
1
= 8.192.
2
F2
should be set in the range 90MHz - 100MHz. Enabling the divide by 2
2
PRESCALE
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
= 4 x 2 x 12.288MHz = 98.304MHz.
12
12
13
13
14.4
14.4
9.6
9.6
9.84
9.84
9.9
9.9
12
12
13
13
13.5
13.5
PRESCALE
= MCLK/
F1
7.5264
8.192
6.947446
7.561846
6.272
6.826667
9.408
10.24
9.178537
9.990243
9.122909
9.929697
7.5264
8.192
6.947446
7.561846
6.690133
7.281778
= F2/F1
1
PD, January 2009, Rev 4.0
- see Figure 75). The PLL
R
7H
8H
6H
7H
6H
6H
9H
AH
9H
9H
9H
9H
7H
8H
6H
7H
6H
7H
Production Data
N
86C2H
3126H
F28BH
8FD5H
45A1H
D3A0H
6872H
3D70H
2DB4H
FD80H
1F76H
EE00H
86C2H
3126H
F28BH
8FD5H
B0ACH
4822H
K
74