Registers
STA309A
22/67
Doc ID 13855 Rev 4
7.2 Register
description
7.2.1 Configuration
register A (0x00)
The STA309A supports sample rates of 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz,
176.4 kHz, 192 kHz, and 2.8224 MHz DSD. Therefore, the internal clocks are:
z
65.536 MHz for 32 kHz
z
90.3168 MHz for 44.1 kHz, 88.2 kHz, 176.4 kHz, and DSD
z
98.304 MHz for 48 kHz, 96 kHz, and 192 kHz
The external clock frequency provided to the XTI pin must be a multiple of the input sample
frequency (fs). The relationship between the input clock and the input sample rate is
determined by both the MCSn and the IRn (input rate) register bits. The MCSn bits
determine the PLL factor generating the internal clock and the IRn bits determine the
oversampling ratio used internally.
7
6
5
4
3
2
1
0
COS1
COS0
DSPB
IR1
IR0
MCS2
MCS1
MCS0
1
0
0
0
0
0
1
1
Table 9.
MSC bits
Bit
RW
RST
Name
Description
0
RW
1
MCS0
Master clock select: selects the ratio between the input
I
2
S sample frequency and the input clock.
1
RW
1
MCS1
2
RW
0
MCS2
Table 10.
MSC sample rates
Input sample rate
fs (kHz)
IR
MCS[2:0]
1XX
011
010
001
000
32, 44.1, 48
00
128 * fs
256 * fs
384 * fs
512 * fs
768 * fs
88.2, 96
01
64 * fs
128 * fs
192 * fs
256 * fs
384 * fs
176.4, 192
10
64 * fs
128 * fs
192 * fs
256 * fs
384 * fs
DSD
11
2 * fs
4 * fs
6 * fs
8 * fs
12 * fs