sta339bws STMicroelectronics, sta339bws Datasheet - Page 62

• Manufacturer Part Number: sta339bws
• Description: 2.1-channel High-efficiency Digital Audio System
• Manufacturer: STMicroelectronics

Register description
6.12.21
Table 72.
62/77
Index (decimal)
19
20
21
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
…
…
0
1
2
3
4
5
Over-current post-scale
The STA339BWS provides a simple mechanism for reacting to over-current detection in the
power-block. When the ocwarn input is asserted, the over-current post-scale value is used
in place of the normal post-scale value to provide output attenuation on all channels. The
default setting provides 3 dB of output attenuation when ocwarn is asserted.
The amount of attenuation to be applied in this situation can be adjusted by modifying the
Over-current Post-scale value. As with the normal post-scale, this scaling value is a 24-bit
signed fractional multiplier, with 0x800000 = -1 and 0x7FFFFF = 0.9999998808. By default,
the over-current post-scale factor is set to
applied, it remains until the device is reset.
RAM block for biquads, mixing, scaling and bass management
Index (hex)
0x2C
0x2D
0x2A
0x2B
0x2E
0x2F
0x00
0x01
0x02
0x03
0x04
0x05
0x13
0x14
0x15
0x27
0x28
0x29
0x30
0x31
0x32
0x33
0x34
0x35
…
…
Low-pass 2
Channel 1/2 - Biquad 5
Channel 1 - Post-Scale
Channel 2 - Post-Scale
Hi-pass 2
Channel 1 - Pre-Scale
Channel 2 - Pre-Scale
Channel 1 - Biquad 1
Channel 1 - Biquad 2
Channel 1 - Biquad 4
Channel 2 - Biquad 1
Channel 2 - Biquad 4
RAM block setting
Channel 3 - Biquad
for XO = 000
for XO = 000
for XO≠000
for XO≠000
nd
…
…
nd
Order filter
Order filter
0x5A9DF7
. Once the over-current attenuation is
C1H10(b1/2)
C1H12(a1/2)
C1H14(b0/2)
C12H0(b1/2)
C12H2(a1/2)
C12H4(b0/2)
Coefficient
C3H0(b1/2)
C3H2(a1/2)
C3H4(b0/2)
C1H11(b2)
C1H13(a2)
C12H1(b2)
C12H3(a2)
C3H1(b2)
C3H3(a2)
C1PreS
C2PreS
C1PstS
C2PstS
C1H20
C1H44
C2H10
C2H11
C2H44
…
…
STA339BWS
0x7FFFFF
0x7FFFFF
0x7FFFFF
0x7FFFFF
0x000000
0x000000
0x000000
0x000000
0x400000
0x000000
0x400000
0x000000
0x000000
0x400000
0x000000
0x000000
0x000000
0x000000
0x400000
0x000000
0x000000
0x000000
0x000000
0x400000
Default
…
…