AK4650 Datasheet, PDF (23/86 Pages) Asahi Kasei Microsystems – 16Bit ΔΣ CODEC with MIC/HP/SPK-AMP & TSC

[AK4650]
■ Audio Sample Rate
Sample Rate for DAC and ADC is controlled by register 2CH and 32H, respectively. 16bit data in D15(MSB) to D0 show
unsigned value from 0 to 65535, representing the exact sampling frequency in Hz. These sample rate setting is done at
VRA bit = “1” of Extended Audio Status and Control Register(2Ah).
Sample Rate (kHz)
Data in D15 – D0
8.0
1F40H
11.025
2B11H
16.0
3E80H
22.05
5622H
24.0
5DC0H
32.0
7D00H
44.1
AC44H
48.0
BB80H
Table 4. Audio Sample Rate
The AK4650 supports these discrete frequencies. When any other codes is written in this register, the AK4650 operates at
the sampling rate rounded to the closest one in Table 4 by decoding only D15-12 bits. If D15-12 = 5H, the AK4650
operates at 22.05kHz or 24kHz when D11 = “0” or “1”, respectively (Table 5).
D15 – D12
D11
Sample Rate (kHz)
0H,1H
x
8.0
2H
x
11.025
3H
x
16.0
4H
x
22.05
5H
0
1
22.05
24.0
6H
x
24.0
7H,8H
x
32.0
9H,AH
x
44.1
BH-FH
x
48.0
Table 5. Audio Sample Rate (x: Don’t care)
At VRA bit = “0”, 2CH and 32H are fixed to “BB80H” and cannot be written. When VRA bit is set to “0”, 2CH and 32H
register are set to “BB80H” automatically.
And the change of sample rate will be executed on the fly.
MS0502-E-01
- 23 -
2007/04