Data Emulation And Data Measurement - ETAS FETK-S1.1 User Manual

ETAS
4.7

Data Emulation and Data Measurement

The FETK-S1.1 is a serial FETK using DAP as the primary microcontroller inter-
face. Typical of all serial ETKs, XETKs and FETKs, the RAM used for data emu-
lation and data measurement is not accessible by the FETK until the
microcontroller is powered up and the startup handshake is performed.
Serial FETKs use the ETAS two page concept, consisting of both a Reference
and a Working page.
The Reference Page is located in the ECU flash and can not be modified by a
simple write access. All changes to the Reference Page must be done via Flash
programming.
The Working Page is typically located within the microcontroller's ED RAM. The
Working Page may be a portion of or the entire size of the ED RAM. The ED RAM
used for the emulation of calibration data must not be used by the ECU soft-
ware directly as general purpose RAM. It is recommended that the ED RAM is
permanently powered by the FETK or ECU. The FETK/INCA has the complete
control over the RAM used as Working Page and it's contents. When enabling
data emulation, the FETK establishes a basic start-up configuration of the data
in the Working Page by copying the corresponding data in the Flash to the emu-
lation space.
To enable calibration, the Working Page must be activated. The process of
switching from the Reference Page to the Working Page and vice versa is
known as page switching.
The FETK-S1.1 supports Protocol Based page switching for all supported
microcontrollers. Page switching is done in microcontroller software by switch-
ing the overlay memory on (Working Page) and off (Reference Page) using
microcontroller overlay registers. The FETK-S1.1 does not directly control the
microcontroller overlay registers. Instead the FETK-S1.1 and microcontroller
software use a simple communication method with a shared mailbox in RAM.
The FETK uses this mailbox to request and monitor page switching; the micro-
controller software is responsible to service this mailbox and perform the page
switches. Using an overlay modification description, also in RAM, the FETK pro-
vides the necessary information of how the overlay registers need to be modi-
fied to realize the page switch which is requested.
The FETK-S1.1 can access both the Reference Page and the Working Page,
regardless of which is active from the microcontroller's point of view.
Another important restriction is that no access to the memory is possible, while
the ECU is not running. To enable a cold start measurement in spite of this
restriction, the cold start measurement procedure is defined to give the user
the feeling of a parallel FETK.
FETK-S1.1 - User's Guide
Hardware Description
24