ETAS
Hardware Description
BR_XETK-S1.0 - User’s Guide
21
4.5
ECU Voltage Supervisor
The ECU voltage (VDDP) is monitored by the XETK to recognize whether the
ECU is switched on or off. Additionally the ECU RAM standby voltage (VDDS-
BRAM) is monitored to determine if the standby RAM content is still valid.
These two signals are only used for monitoring therefore the load current is
negligible.
The BR_XETK-S1.0 provides two possibilities to supply and supervise the ECU
RAM standby voltage:
• The BR_XETK-S1.0 monitors the VDDSBRAM supply on board the XETK.
The microcontroller’s standby power supply pin must be connected to
the XETK pin VDDSBRAM.
• At the through-hole solder pad CON3 the BR_XETK-S1.0 can additionally
monitor the VDDSBRAMsense voltage if it is provided by the ECU. The
microcontroller’s standby power supply pin must be connected to the
XETK pin VDDSBRAMsense. The microntroller’s standby power supply
may be provided by the ECU or by the XETK.
NOTE
The BR_XETK-S1.0 only allows switching between reference page and work-
ing page if there is a valid voltage at the sense pin and the working page has
been initialized by the calibration and development system.
