Trigger modes

Overview

The BR_XETK-S3.0 supports the following trigger modes:

  • Pinless triggering

  • Timer triggering

  • Trace triggering by value

Note  

Only the BR_XETK-S3.0A supports trace triggering.

Pinless triggering

The trigger mode "Pinless Triggering" uses the microcontroller’s internal Development Trigger Semaphore (DTS) for triggering.

Startup handshake

The COMDATA trigger register is used to generate an ETK startup handshake. The ECU must ensure that all memory ECC initializations have been completed prior to the startup handshake.

XETK trigger generation

Initialization

After the startup handshake and measurement is enabled, the XETK is waiting for triggers from the ECU software.

Application running

To generate triggers, the ECU software sets bits in the trigger register "CBS_TRIG" by writing the associated bits in the trigger setting register "CBS_TRIGS".

Each bit of the trigger setting register "CBS_TRIGS" corresponds to a bit in the same position in the trigger register "CBS_TRIG", each of them corresponding to an XETK hardware trigger.

The XETK periodically polls the trigger register "CBS_TRIG" via IO_READ_TRIG for detecting triggers. The polling rate is determined by the fastest measurement raster and is configurable with a 50 μs default.

Active bits in trigger register "CBS_TRIG" are automatically cleared by the CPU when the register is read by the BR_XETK-S3.0 via IO_READ_TRIG.For generating triggers, the ECU software sets bits in the trigger register "CBS_TRIG" by writing the associated bits in the trigger setting register "CBS_TRIGS".

Timer triggering

The trigger mode "Timer Triggering" uses four internal timers of the BR_XETK-S3.0 for triggering. A fixed configurable period is used for triggering.

The time intervals between trigger events are in accordance with the configured timer values. This values and their resolution have to be defined in the A2L file. Available settings are:

  • Minimum time interval 100 μs

  • Maximum period duration 1 s

  • Timer resolution 1 μs

The timers work in an asynchronous manner to the ECU.

Trace triggering

The BR_XETK-S3.0 provides support for up to 64 trace triggers. The trace triggers are defined within a section of RAM covered by a trace window. Both the trace window and trace triggers are defined in the XETK’s configuration and/or A2L file. A write by the microcontroller software to a trace trigger location causes a trace trigger. The trace trigger events to the BR_XETK-S3.0 are synchronous to the microcontroller software. Variables assigned to a measurement raster using a trace trigger are acquired from the XETK’s trace mirror, not directly via DAP. The BR_XETK-S3.0 supports value based data trace trigger up to 255 value (up to 64 used in a single setup).

Requirements for trace triggering by the BR_XETK-S3.0:

  • The triggers for different rasters/events have same address, but use different values.

  • The address must be 32 bit aligned.

  • The write must be 32 bit width (the upper 24 bits must be ‘0’).

  • The value 0x0 is not a valid trigger number.

Note  

It is not possible to use the BR_XETK-S3.0 configured with trace triggers and adebugger with program / data trace simultaneously.