TLE9221SX Datasheet, PDF (14/91 Pages) Infineon Technologies AG – FlexRay Transceiver

TLE9221SX
Overview Functional Blocks
TxD
TxEN
BGE
Transmitter on
BP
BM
“Data_1” “Data_0”
“Data_1”
The Transmitter can only be
t
activated while TxD = “low”
Transmitter off
“Idle”
t
Transmitter on
t
Transmitter off
“Data_0” “Data_1” “Data_0” “Data_1”
“Idle”
t
RxEN
t
RxD
t
Figure 7 FlexRay physical layer bus signals with Bus Guardian Interface
The Receiver of the TLE9221SX is active in all non-low power operating modes. Similar to the TxD input, the RxD
output indicates a “Data_1” signal on the FlexRay bus by a logical “high” signal and the “Data_0” signal by a logical
“low” signal.
In every low power mode, the TxD and TxEN input pins are disabled. The RxD output pin is used to indicate the
wake-up flag, while the transceiver is in low power mode (see Table 5).
5.4
Bus Guardian Interface
The Bus Guardian Interface comprises two digital signals:
• The BGE (Bus Guardian Enable) input pin.
• The RxEN (Receive Enable Not) output pin.
The logical I/O levels of the input and the output pin are adapted to the reference voltage uV_IO. In case uV_IO is not
available or in undervoltage condition, the RxEN output is set to logical “low” and the input pin BGE is set to its
default condition (see Table 2).
The Bus Guardian logic block handles the connection to the Transmitter and the Receiver. The Central State
Machine provides the interface to other TLE9221SX function blocks and handles the dependency on the selected
mode of operation (see Figure 8).
Data Sheet
14
Rev. 1.10, 2013-07-15