sta003t STMicroelectronics, sta003t Datasheet - Page 23

• Manufacturer Part Number: sta003t
• Description: Mpeg 2.5 Layer Iii Audio Decoder
• Manufacturer: STMicroelectronics

RUN
Address: 0x72
Type: RW
Software Reset: 0x00
Hardware Reset: 0x00
Setting this register to 1, STA003T leaves the idle
state, starting the decoding process.
The Microcontroller is allowed to set the RUN
flag, once all the control registers have been in-
itialized.
TREBLE_FREQUENCY_LOW
Address: 0x77
Type: RW
Software Reset: 0x00
Hardware Reset: 0x00
TREBLE_FREQUENCY_HIGH
Address: 0x78
Type: RW
Software Reset: 0x00
Hardware Reset: 0x00
The registers TREBLE_FREQUENCY_HIGH and
TREBLE_FREQUENCY_LOW, logically concate-
nated as a 16 bit wide register, are used to select
the frequency, in Hz, where the selected fre-
quency is +12dB respect to the stop band.
By setting these registers, the following rule must
be kept:
Treble_Freq < Fs/2
TF15 TF14 TF13 TF12 TF11 TF10
MSB
MSB
MSB
TF7
b7
b7
b7
X
TF6
b6
b6
b6
X
TF5
b5
b5
b5
X
TF4
b4
b4
b4
X
TF3
b3
b3
b3
X
TF2
b2
b2
b2
X
TF1
TF9
b1
b1
b1
X
LSB
RUN
LSB
LSB
TF0
TF8
b0
b0
b0
BASS_FREQUENCY_LOW
Address: 0x79
Software Reset: 0x00
Hardware Reset: 0x00
BASS_FREQUENCY_HIGH
Address: 0x7A
Software Reset: 0x00
Hardware Reset: 0x00
The registers BASS_FREQUENCY_HIGH and
BASS_FREQUENCY_LOW, logically concate-
nated as a 16 bit wide register, are used to select
the frequency, in Hz, where the selected fre-
quency is -12dB respect to the pass-band. By
setting the BASS_FREQUENCY registers, the
following rules must be kept:
Bass_Freq <= Treble_Freq
Bass_Freq > 0
(suggested range: 20 Hz < Bass_Freq < 750 Hz)
Example:
Bass = 200Hz
Treble = 3kHz
TFS
BFS
BF15 BF14 BF13 BF12 BF11 BF10
15 14 13 12 11 10 9
15 14 13 12 11 10 9
MSB
MSB
0
0
BF7
b7
b7
0
0
0
0
BF6
b6
b6
0
0
1
0
BF5
b5
b5
0
0
1
0
BF4
b4
b4
8
1
8
0
7
1
7
1
BF3
b3
b3
6
0
6
1
5
1
5
0
BF2
b2
b2
4
1
4
0
3
1
3
1
BF1
BF9
STA003T
b1
b1
2
0
2
0
1
0
1
0
LSB
BF0
LSB
BF8
23/32
b0
b0
0
0
0
0