TLE9221SX Datasheet, PDF (17/91 Pages) Infineon Technologies AG – FlexRay Transceiver

TLE9221SX
Overview Functional Blocks
The EN and STBN pins control the modes of operation. The pins are connected to the Central State Machine via
an input filter. The input filter protects the transceiver TLE9221SX against unintentional mode changes caused by
spikes on the EN and STBN.
The ERRN output signals failures, diagnostic and status information to the external host controller. The
TLE9221SX also contains a Status Information Register. Access to the Status Information Register is given by the
Host Interface (see details Chapter 6).
Table 6 Modes of operation¹⁾
STBN
EN
Mode of Operation
“high”
“high”
BD_Normal
“high”
“low”
BD_ReceiveOnly
“low”
“high”
BD_GoToSleep, automatically transferred to BD_Sleep
“low”
“low”
BD_Standby
1) No undervoltage flag and no wake-up flag is set.
5.6
Wake-up Detector
The Wake-up Detector is a separate internal function block to detect wake-up events, be it a local or a remote
wake-up event. The Wake-up Detector also enables the filtering unit to differentiate between real wake-up signals
and floating signals or glitches on the wake-up lines. Active in every operation mode, and also in the BD_Normal
or BD_ReceiveOnly mode, the Wake-up Detector ensures that no wake-up signal gets lost due to a concurrent
change of the operating mode. The Wake-up Detector provides feedback on the wake-up information to the
Central State Machine for further processing (details see Chapter 7).
5.7
Power Supply Interface
The Power Supply Interface is the interface from the bus driver to the external supply voltages. It hosts the inputs
to the power supplies V_BAT and V_CC and also the level shift input to the reference voltage V_IO (according to the
FlexRay EPL, version 3.0.1, functional class: “Bus driver logic level adaptation”).
To enable the control of external circuitry, like a voltage regulator for example, the Power Supply Interface of the
TLE9221SX provides an INH output (according to the FlexRay EPL, version 3.0.1, functional class: “Bus driver
voltage regulator control”).
All power supplies and the reference voltage are monitored and undervoltage conditions are indicated via the
ERRN output on the Host Interface (details see Chapter 8).
5.8
Bus Failure Detector
The Bus Failure Detector monitors the data stream on the BM and BP I/O pins and compares the bus data with
the digital data stream available at the Communication Controller Interface. Discrepancies between the bus data
and the digital data are interpreted as a bus failure. The Bus Failure Detector is active only in BD_Normal mode.
All detected failures are signaled on the ERRN output by the Host Interface (see Chapter 10).
5.9
Central State Machine
The Central State Machine is the main logic block of the TLE9221SX. It controls all functions of the TLE9221SX,
the failure management as well as the power-up and power-down operations. The Central State Machine also
provides some internal registers to store status, diagnostic and failure information.
• Information about the operating mode handling (see Chapter 9)
• Information about the Status Information Register (see Chapter 6)
• Information about the power management (see Chapter 8)
• Information about the bus failure flag (see Chapter 10)
Data Sheet
17
Rev. 1.10, 2013-07-15