tda9870ah NXP Semiconductors, tda9870ah Datasheet - Page 31

• Manufacturer Part Number: tda9870ah
• Description: Digital Tv Sound Processor Dtvsp
• Manufacturer: NXP Semiconductors

Philips Semiconductors
10.3
As a slave receiver, the TDA9870A provides 46 registers for storing commands and data. These registers are accessed
via so-called subaddresses. A subaddress can be thought of as a pointer to an internal memory location.
Table 9 I
Table 10 Explanation of Table 9
It is allowed to send more than one data byte per transmission to the TDA9870A. In this event, the subaddress is
automatically incremented after each data byte, resulting in storing the sequence of data bytes at successive register
locations, starting at SUBADDRESS. A transmission can start at any valid subaddress. Each byte is acknowledged with
ACK (acknowledge).
There is no ‘wrap-around’ of subaddresses.
Commands and data are processed as soon as they have been completely received. Functions requiring more than one
byte will, thus, be executed only after all bytes for that function have been received. If the transmission is terminated
(STOP condition) before all bytes have been received, the incomplete data for that function are ignored.
Table 11 Format for a transmission employing auto-increment of subaddresses
Note
1. n data bytes with auto-increment of subaddresses.
Data patterns sent to the various subaddresses are not checked for being illegal or not at that address, except for the
functions of volume, bass and treble control, bass boost and level adjust.
Detection of a STOP condition without a preceding acknowledge bit is regarded as a bus error. The last operation will
then not be executed.
1999 Dec 20
S
SLAVE ADDRESS
0
ACK
SUBADDRESS
DATA
P
Digital TV Sound Processor (DTVSP)
S
S
Slave receiver mode
2
C-bus; slave address, subaddress and data format
SLAVE ADDRESS
SLAVE ADDRESS
BIT
START condition
7-bit device address
data direction bit (write to device)
acknowledge by slave
address of register to write to
data byte to be written into register
STOP condition
0
0
ACK
ACK
SUBADDRESS
SUBADDRESS
31
FUNCTION
ACK
ACK
BYTE A
DATA
DATA
(1)
DATA
Product specification
TDA9870A
ACK
ACK
P
P