ETAS
Hardware Description
XETK-S30.0 - User’s Guide
24
4.8
Trigger Modes: Overview
The XETK-S30.0 supports the following trigger modes:
• Pinless triggering
• Timer triggering
The trigger mode "Pinless Triggering" uses the microcontroller’s internal Devel-
opment Trigger Semaphore (DTS) for triggering. See also chapter “Pinless Trig-
gering” on page 24.
The trigger mode "Timer Triggering" uses four internal timers of the XETK for
triggering. See also chapter “Timer Triggering” on page 25.
4.9
Pinless Triggering
4.9.1
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 start-up handshake.
4.9.2
XETK Trigger Generation
4.9.2.1
Initialization
After the startup handshake and measurement is enabled, the XETK is waiting
for triggers from the ECU software.
4.9.2.2
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 measure-
ment 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 XETK-S30.0 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".
