XETK-S4.2 - User’s Guide
24
ETAS
Hardware Description
4.9
Trigger Modes: Overview
The XETK-S4.2 supports the following trigger modes:
• Pinless triggering
• Timer triggering.
The trigger mode "Pinless Triggering" uses an internal JTAG register for trigger-
ing. See also chapter "Pinless Triggering" 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.
4.10
Pinless Triggering
4.10.1
Startup Handshake
The registers CBS_TRIG and CBS_OSTATE.OJC are initialized to 0x0 during reset.
When the reset is deactivated (as detected by the /HDRST signal) a special pattern
is written to the OJC[3..1] bits of the CBS_OSTATE register of the CPU by the
XETK via the IO_SET_OJCONF JTAG command. This pattern includes the power
fail status of the standby supply. (No power fail: write "001", Power fail: write
"011").
The ECU software must wait at least 50
μ
s from reset before reading the
CBS_OSTATE register to ensure the XETK-S4.2 has completed the IO_SET_OJ-
CONF operation.
Application running
The ECU software detects the connected XETK by reading CBS_OSTATE register.
Thereafter the ECU software performs basic initilizations and when finished
writes 00005555h to CBS_TRIGS register. The XETK is periodically polling
CBS_TRIG and detects the xxxx5555h pattern. The startup handshake is fin-
ished, the XETK then starts initialization and data acquisition (e.g. coldstart,
checksum, downloads, etc).
4.10.2
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.
Note
The XETK-S4.2 uses the pinless startup and triggering feature with the micro-
controller Infineon AUDO MAX microcontroller family.
