ETAS
Hardware Description
ETK-T2.2 User Guide
22
4.5.4
Data Retention in Data Emulation Memory
The data emulation and measurement data memory physically consists of a
static Dual Port RAM and is permanently supplied with power from the car bat
-
tery, to guarantee that data is preserved even when the ignition is switched off.
If the ECU with ETK is isolated from the battery, all data will be lost. For brief
power interruptions, e.g. during a cold start procedure, buffering is guaranteed
through capacitors for several milliseconds.
4.6
Data Flash Memory
Flash memory is provided on the ETK-T2.2 for permanent storage of emulation
data. Users can copy the contents of the data emulation and measurement
data memory into the flash memory using the operating software. It is recom
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mended that an updated data set is always stored in the flash memory.
The ETK-T2.2 has a circuit which recognizes and stores power failures. If this
circuit detects a longer power failure, and therefore a possible inconsistency of
the emulation data, the ETK controller initiates a copying procedure Flash
memory to DPR upon restart. The Flash memory data is copied to both emula
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tion pages. A green LED on the ETK displays the procedure. The operating soft
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ware announces the procedure by a message in the status line.
4.7
Code Flash Memory
The program code is not emulated by the ETK-T2.2. The program code is
stored in the ECU Flash memory ("on chip" and/or external) and is not modified
by the ETK-T2.2. Only the accessible emulation data areas are emulated by the
ETK-T2.2. The ECU Flash memory can be programmed with the normal Flash
memory programming tools.
4.8
Braindead Flashing (ETK-T2.2B and ETK-T2.2C)
In order to support braindead flashing the ETK-T2.2B/ ETK-T2.2C provides the
hardware prerequisites to allow booting the microcontroller from the ETK
memory and making the flash accessible to the software while the microcon
-
troller is running from the ETK memory. For braindead flashing it is required
that the microcontroller boots from the ETK memory.
NOTE
The Flash memory on the ETK-T2.2 only stores data which exists in the data
emulation and measurement data memory of the ETK-T2.2. The program
code is stored only in the ECU Flash memory.
NOTE
Only ETK-T2.2 versions ETK-T2.2B and ETK-T2.2C support the "Braindead
Flash" function (refer to chapter 9.1 on
52).
