TEA6821T Philips Semiconductors, TEA6821T Datasheet - Page 27

• Manufacturer Part Number: TEA6821T
• Description: ICE car radio
• Manufacturer: Philips Semiconductors

Philips Semiconductors
I
FUNCTIONS
I
The standard I
following definitions. Structure of the I
transceiver with auto increment and expansion to switch a
direct transfer of all transmissions to an output for the radio
front end IC (TEA6810T respectively TEA6811T).
Subaddresses are not used. Data transfer to the
TEA6821T Data sequence: address
The data transfer has to be only in this order. The transfer
direction of the data bytes is defined by the LSB of the
address. The data becomes valid at the output of the
internal latches with the acknowledge of each byte. A stop
condition after any byte can shorten transmission times.
When writing to the transceiver by using the stop condition
before completion of the whole transfer:
September 1993
2
2
C-BUS SPECIFICATION AND I
C-bus specification
The remaining bytes will contain the old information
If the transfer of a byte was not completed, this byte is
lost and the previous information is available.
ICE car radio
2
C-bus specification is expanded by the
2
C-BUS CONTROLLED
Fig.22 High-cut as function of control voltage.
2
C-bus logic: slave
byte 1
byte 2
27
Data transfer to an output of the front end IC.
A data bit in the transceiver of the TEA6821T enables or
disables a direct transfer of all transmissions to an
interface stage for the front end IC.
For a transmission to the front end IC the address and the
data format of the front end IC has to be used.
Hint: The pull-up resistors for the front end interface (pins
6 and 7) should not be connected to the 5 V supply voltage
of the front end IC, otherwise a bus pull-down (pin 53) can
occur during switching off the front end supply when the
interface stage is enabled.
Data transfer to the IF IC (TEA6821T) is independent of
the state of interface stage for the front end IC.
Preliminary specification
TEA6821T