Register description: Sound Terminal compatibility
STA382BW
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Doc ID 022783 Rev 1
7.1.2
Interpolation ratio select
The STA382BW has variable interpolation (oversampling) settings such that internal
processing and FFX output rates remain consistent. The first processing block interpolates
by either 3 times (see
), 2 times or 1 time (pass-through) or provides a 2-times
downsample. The oversampling ratio of this interpolation is determined by the IR bits.
7.1.3 Fault-detect
recovery bypass
The on-chip STA382BW power output block provides feedback to the digital controller using
inputs to the power control block. The FAULT input is used to indicate a fault condition (either
overcurrent or thermal). When FAULT is asserted (set to 0), the power control block attempts
a recovery from the fault by asserting the tri-state output (setting it to 0 which directs the
power output block to begin recovery), holds it at 0 for period of time in the range of 0.1 ms
to 1 second as defined by the fault-detect recovery constant register (FDRC registers 0x2B-
0x2C), then toggles it back to 1. This sequence is repeated as long as the fault indication
exists. This feature is enabled by default, but can be bypassed by setting the FDRB control
bit to 1.
Table 104.
Internal interpolation ratio
Bit
R/W
RST
Name
Description
4:3
R/W
00
IR [1:0]
Selects internal interpolation ratio based on input I
2
S
sampling frequency
Table 105.
IR bit settings as a function of the input sampling rate
Input sampling rate fs (kHz)
IR
1st stage interpolation ratio
32
00
2-times oversampling
44.1
00
2-times oversampling
48
00
2-times oversampling
88.2
01
Pass-through
96
01
Pass-through
176.4
10
2-times downsampling
192
10
2-times downsampling
Table 106.
Fault-detect recovery bypass
Bit
R/W
RST
Name
Description
7
R/W
0
FDRB
0: fault-detect recovery enabled
1: fault-detect recovery disabled
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