WM8990ECS/RV Wolfson Microelectronics, WM8990ECS/RV Datasheet - Page 125

• Manufacturer Part Number: WM8990ECS/RV
• Description: Audio CODECs Stereo CODEC w.Class AB/D speaker driver
• Manufacturer: Wolfson Microelectronics

Specifications of WM8990ECS/RV

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

w
Production Data
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 81) 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 74 provides example PLL settings for generating common SYSCLK frequencies from a variety
of MCLK reference frequencies.
Table 74 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
- see Figure 75). The PLL
R
PD, March 2009, Rev 4.0
7H
8H
6H
7H
6H
6H
9H
AH
9H
9H
9H
9H
7H
8H
6H
7H
6H
7H
N
WM8990
86C2H
3126H
F28BH
8FD5H
45A1H
D3A0H
6872H
3D70H
2DB4H
FD80H
1F76H
EE00H
86C2H
3126H
F28BH
8FD5H
B0ACH
4822H
K
125