AN332
Rev. 0.8
157
Property 0x3300. AM_SOFT_MUTE_RATE
Sets the attack and decay rates when entering or leaving soft mute. The value specified is multiplied by 4.35 dB/s
to come up with the actual attack rate. 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 when in powerup mode. The default rate is 278 dB/s.
Available in: All
Default: 0x0040
Actual Rate: SMRATE x 4.35
Units: dB/s
Step: 1
Range: 1–255
Property 0x3301. AM_SOFT_MUTE_SLOPE
Configures attenuation slope during soft mute in dB attenuation per dB SNR below the soft mute SNR threshold.
Soft mute attenuation is the minimum of SMSLOPE x (SMTHR – SNR) and SMATTN. The recommended
SMSLOPE value is CEILING(SMATTN/SMTHR). SMATTN and SMTHR are set via the
AM_SOFT_MUTE_MAX_ATTENUATION and AM_SOFT_MUTE_SNR_THRESHOLD properties. 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
when in powerup mode. The default slope is 1 dB/dB for AMRX component 5.0 or later and 2 dB/dB for AMRX
component 3.0 or earlier.
Available in: All
Default: 0x0002 (Si4730/31/34/35/36/37-B20 and earlier, Si4740/41/42/43/44/45-C10 and earlier)
0x0001 (all others)
Units: dB/dB
Range: 1–5
Bit
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Name
SMRATE[15:0]
Bit
Name
Function
15:0
SMRATE
AM Soft Mute Rate.
Determines how quickly the AM goes into soft mute when soft mute is enabled. The
actual rate is calculated by taking the value written to the field and multiplying it with
4.35 dB/s. The default rate is 278 dB/s (SMRATE[15:0] = 0x0040).
Bit
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
Name
0
0
0
0
0
0
0
0
0
0
0
0
SMSLOPE[3:0]
Bit
Name
Function