Register description
STA335W
5.1.1
Master clock select
Table 10. Master clock select
Bit
R/W
RST
Name
Description
0
R/W
1
1
R/W
1
2
R/W
0
MCS0
MCS1
MCS2
Selects the ratio between the input I2S sample
frequency and the input clock.
The STA335W supports sample rates of 32 kHz, 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz,
176.4 kHz, and 192 kHz. Therefore the internal clock is:
● 32.768 MHz for 32 kHz
● 45.1584 MHz for 44.1 kHz, 88.2 kHz, and 176.4 kHz
● 49.152 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 MCSx and the IR (input rate) register bits. The MCSx bits determine the PLL factor
generating the internal clock and the IR bit determines the oversampling ratio used
internally.
Table 11. Input sampling rates
Input sample rate
IR
fs (kHz)
MCS[2:0]
101
100
011
010
001
000
32, 44.1, 48
88.2, 96
176.4, 192
00 576 * fs 128 * fs 256 * fs 384 * fs 512 * fs 768 * fs
01
NA
64 * fs 128 * fs 192 * fs 256 * fs 384 * fs
1X
NA
32 * fs 64 * fs 96 * fs 128 * fs 192 * fs
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