Cirrus Logic CS44600 - Manual (Page 55)

DS633F1 55
CS44600
7.8 Master Volume Control - Integer (address 07h)
7.8.1 Master Volume Control - Integer (MSTR_IVOL[7:0])
Default = 00000000
Function:
The Master Volume Control - Integer register allows global control of the signal levels on all channels in
1 dB increments from +24 to -127 dB. Volume settings are decoded as shown in Table 6. The volume
changes are implemented as specified by the Soft and Zero Cross bits (SZC[1:0]). All volume settings
greater than 00011000b are equivalent to +24 dB. Binary values for integer volume settings less than
0 dB are in two’s complement form.
7.9 Master Volume Control - Fraction (address 08h)
7.9.1 Master Volume Control - Fraction (MSTR_FVOL[1:0])
Default = 00
00 - +0.00 dB
01 - +0.25 dB
10 - +0.50 dB
11 - +0.75 dB
Function:
The Master Volume Control - Fraction register is an additional offset to the value in the Master Volume
Control - Integer register and allows global control of the signal levels on all channels in 0.25 dB incre-
ments. Volume settings are decoded as shown in Table 7. These volume changes are implemented as
specified by the Soft and Zero Cross bits (SZC[1:0]). All volume settings greater than 00011000b are
equivalent to +24 dB. Binary values for integer and fractional volume settings less than 0 dB are in two’s
complement form.
To calculate from a positive decimal integer:fraction value to a binary positive integer:fraction value, do
the following:
1. Convert the decimal integer to binary. This is MSTR_IVOL[7:0].
2. Select the bit representation of the desired 0.25 fractional increment. This is MSTR_FVOL[1:0].
To calculate from a negative decimal integer:fraction value to a binary, 2’s complement integer:fraction
value, do the following:
7 6 5 4 3 2 1 0
MSTR_IVOL7 MSTR_IVOL6 MSTR_IVOL5 MSTR_IVOL4 MSTR_IVOL3 MSTR_IVOL2 MSTR_IVOL1 MSTR_IVOL0
MSTR_IVOL[7:0] Hex Value Volume Setting
0001 1000 18 +24 dB
0001 0111 17 +23 dB
0000 0001 01 +1 dB
0000 0000 00 0 dB
1111 1111 FF -1 dB
1111 1110 FE -2 dB
1000 0001 81 -127 dB
Table 6. Master Integer Volume Settings
7 6 5 4 3 2 1 0
RESERVED RESERVED RESERVED RESERVED RESERVED RESERVED MSTR_FVOL1 MSTR_FVOL0