TDA9875 Philips Semiconductors, TDA9875 Datasheet - Page 82

• Manufacturer Part Number: TDA9875
• Description: Digital TV Sound Processor DTVSP
• Manufacturer: Philips Semiconductors

Philips Semiconductors
10.4.9.2
Table 107 Subaddress 253
10.4.10 D
10.4.10.1 Description
There will be several devices in the digital TV sound
processor family, with TDA9875 being the first member.
This byte is used to identify the individual family members
purely for Philips internal use.
The first version will have the identification 00000000.
10.4.10.2 Definition
Table 108 Subaddress 254
10.4.11 S
10.4.11.1 Description
It is likely that during the life time of this family of devices
several versions of the DSP software will be made, e.g., to
accommodate new application concepts, respond to
customer wishes, etc. This byte is used to identify the
different releases purely for Philips internal use.
The first version will have the identification 00000000.
Table 110 General format for entering the expert mode and writing coefficients into the TDA9875
Table 111 Explanation of Table 110
1998 Feb 13
S
SLAVE ADDRESS
0
ACK
10000000
CRAM ADDRESS
DATA
P
MSB
MSB
S SLAVE ADDRESS 0 ACK
B7
B7
Digital TV Sound Processor (DTVSP)
B6
B6
OFTWARE IDENTIFICATION CODE
EVICE IDENTIFICATION CODE
Definition
BIT
B5
B5
B4
B4
B3
B3
START condition
7-bit device address
data direction bit (write to device)
acknowledge
pattern to enter the expert mode
start address of coefficient RAM to write to
data byte containing part of a coefficient
STOP condition
10000000
B2
B2
B1
B1
ACK CRAM ADDRESS ACK
LSB
LSB
B0
B0
82
10.4.11.2 Definition
Table 109 Subaddress 255
10.5
In addition to the slave receiver and slave transmitter
modes previously described, there is a special ‘expert’
mode that gives direct write access to the internal CRAM
of the DSP.
In this mode, transferred data contain 12-bit-wide
coefficients. As those coefficients bypass on-chip
coefficient look-up tables for many functions, they directly
influence the processing of signals within the DSP.
This mode must be used with great care. It can be used to
create user-defined characteristics, such as a tone control
with different corner frequencies or special boost/cut
characteristics to correct the low-frequency loudspeaker
and/or cabinet frequency responses.
MSB
B7
Expert mode
B6
FUNCTION
B5
B4
DATA
B3
ACK
Preliminary specification
B2
DATA
TDA9875
B1
ACK P
LSB
B0