Datasheet

TEF6901A_3 © NXP B.V. 2008. All rights reserved.
Product data sheet Rev. 03 — 20 March 2008 45 of 107
NXP Semiconductors
TEF6901A
Integrated car radio
[1] When for an external audio source dynamic compression is enabled (bit COMP is logic 1) the MTC setting
controls the t
recovery
compression timing, t
attack
has a fixed value of 20 ms; see Table 80.
[2] The attack time is the time, which the weak signal processing needs to realize a full control change for a
level voltage change between HIGH level (where the weak signal processing is inactive) and 0.75 V level
voltage.
[3] The recovery time is the time needed for the full control change when the level voltage rises from 0.75 V to
HIGH level.
8.2.14 Write mode: data byte SNC
Table 56. Soft mute weak signal processing control speed setting
[1]
MTC2 MTC1 MTC0 t
attack
[2]
t
recovery
[3]
0 0 0 0.01 s 0.01 s
0 0 1 0.01 s 0.03 s
0 1 0 0.03 s 0.1 s
0 1 1 0.1 s 0.1 s
1 0 0 0.1 s 0.2 s
1 0 1 0.2 s 0.2 s
1 1 0 0.4 s 0.4 s
1 1 1 0.4 s 0.8 s
Table 57. SNC - format of data byte 0Ch with default setting
7 6 5 4 3 2 1 0
SST3 SST2 SST1 SST0 SSL1 SSL0 HCMP HCSF
01110100
Table 58. SNC - data byte 0Ch bit description
Bit Symbol Description
7 to 4 SST[3:0] SNC start; start setting of the stereo noise control; see
Table 59 and
Figure 25
3 and 2 SSL[1:0] SNC slope; slope setting of the stereo noise control (α
sep
/V
eq.LEVEL
);
see
Figure 25
00 = 38 dB/V
01 = 51 dB/V
10 = 63 dB/V
11 = 72 dB/V
1 HCMP HCC control source
0 = high cut control is only controlled by the level information
1 = high cut control is controlled by level, USN and WAM
0 HCSF HCC minimum bandwidth; combined control with bit HCSFH;
see
Table 49, Table 60 and Figure 26