TDA9875AH Philips Semiconductors, TDA9875AH Datasheet - Page 38

• Manufacturer Part Number: TDA9875AH
• Description: Digital TV Sound Processor DTVSP
• Manufacturer: Philips Semiconductors

Philips Semiconductors
10.3.4
The three bytes together constitute a 24-bit frequency
control word to represent the sound carrier (i.e. mixer)
frequency in accordance with the following formula:
where:
Example: A 5.5 MHz sound carrier frequency will be
generated by sending the following sequence of data
bytes to the TDA9875A (data = 7509333 in decimal
notation or 72555 in hexadecimal):
01110010 10010101 01010101.
As three bytes are required to define a carrier frequency,
execution of this command starts only after all bytes have
been received. If an error occurs, e.g. a premature STOP
condition, partial data for this function is ignored.
The default setting at power-up is 0000 0000 for all three
bytes.
Most significant part at subaddress 3 and least significant
part at subaddress 5 (see Table 20).
1999 Dec 20
data
data = 24-bit frequency control word
f
f
2
Digital TV Sound Processor (DTVSP)
mix
clk
24
= 12.288 MHz (clock frequency of mixer)
=
= 16777216 (number of steps in a 24-bit word size).
= desired sound carrier frequency
f
-------- -
f
C
mix
clk
ARRIER
2
24
1
FREQUENCY REGISTER
38
Table 20 Subaddresses 3 to 5
ADDRESS
SUB-
3
4
5
7 (MSB)
0 (LSB)
BIT
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
carrier 1 frequency;
most significant part
carrier 1 frequency
carrier 1 frequency;
least significant part
DESCRIPTION
Product specification
TDA9875A