
A N 5 4 3
78
Rev. 0.9
Property 0x040B FM_SOFT_MUTE_USN_ATTENUATION
The FM_SOFT_MUTE_USN_ATTENUATION property sets the limits for soft mute attenuation when driven by
USN. The CTS bit (and optional interrupt) is set when it is safe to send the next command. This property may only
be set or read in powerup mode.
Si475x-A20 and earlier, Si475x-A40 and later: This property is not available.
Si475x-A30, Default: 0x0000
Units: dB
Property 0x040C FM_SOFT_MUTE_USN_ATTACK_TIME
The FM_SOFT_MUTE_USN_ATTACK_TIME property sets maximum time in ms it takes to mute the audio based
on USN. The CTS bit (and optional interrupt) is set when it is safe to send the next command. This property may
only be set or read in powerup mode.
Si475x-A20 and earlier, Si475x-A40 and later: This property is not available.
Si475x-A30, Default: 0x0080
Units: ms
FM_SOFT_MUTE_USN_ATTENUATION
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
YMIN[7:0]
YMAX[7:0]
0x00
0x00
Bit
Name
Function
15:8
YMIN[7:0]
Sets the minimum attenuation in dB for USN-based soft mute.
Default is 0. Range is 0–63.
7:0
YMAX[7:0]
Sets the maximum attenuation in dB for USN-based soft mute.
Default is 0. Range is 0–63.
FM_SOFT_MUTE_USN_ATTACK_TIME
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
ATTACK[15:0]
0x0080
Bit
Name
Function
15:0
ATTACK[15:0]
Sets the USN-based soft mute attack time in ms. Note that there
will be 16 ms of filter delay for USN metric before softmute can
engage/disengage. Default is 128. Range is 1–32767.