tda5251f1 Infineon Technologies Corporation, tda5251f1 Datasheet - Page 24

• Manufacturer Part Number: tda5251f1
• Description: Ask/fsk 315mhz Wireless Transceiver
• Manufacturer: Infineon Technologies Corporation

TDA5251 F1
Version 1.0
Functional Description
Confidential
2
I
C Bus Mode
In this mode the BusMode pin (pin 2) = LOW and the EN pin (pin 24) = LOW.
Data Transition:
Data transition on the pin BusData can only occur when BusCLK is LOW. BusData transitions while
BusCLK is HIGH will be interpreted as start or stop condition.
Start Condition (STA):
A start condition is defined by a HIGH to LOW transition of the BusData line while BusCLK is HIGH.
This start condition must precede any command and initiate a data transfer onto the bus.
Stop Condition (STO):
A stop condition is defined by a LOW to HIGH transition of the BusData line while BusCLK is HIGH.
This condition terminates the communication between the devices and forces the bus interface into
the initial state.
Acknowledge (ACK):
Indicates a successful data transfer. The transmitter will release the bus after sending 8 bit of data.
During the 9th clock cycle the receiver will set the SDA line to LOW level to indicate it has received
the 8 bits of data correctly.
Data Transfer Write Mode:
To start the communication, the bus master must initiate a start condition (STA), followed by the 8bit
chip address. The chip address for the TDA5251 is fixed as „1110000“ (MSB at first). The last bit
(LSB=A0) of the chip address byte defines the type of operation to be performed:
A0=0, a write operation is selected and A0=1 a read operation is selected.
After this comparison the TDA5251 will generate an ACK and awaits the desired sub address byte
(00H...0FH) and data bytes. At the end of the data transition the master has to generate the stop
condition (STO).
Data Transfer Read Mode:
To start the communication in the read mode, the bus master must initiate a start condition (STA),
followed by the 8 bit chip address (write: A0=0), followed by the sub address to read (80H, 81H),
followed by the chip address (read: A0=1). After that procedure the data of the selected register
(80H, 81H) is read out. During this time the data line has to be kept in HIGH state and the chip sends
out the data. At the end of data transition the master has to generate the stop condition (STO).
Preliminary Specification
24
2003-02-18