iSYSTEM, March 2017
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50-pin Samtec MPC5xxx Nexus 16-bit Cable Adapter
Ordering code
IC50156
This adapter is used to connect the iC5000 / iC5500 / iC5700 development system to Freescale MPC5xxx or ST
SPC56 based target via Nexus debug interface. It connects between the Debug/Trace module and the target
debug connector. It can be used for targets featuring 50-pin Samtec ERF8-025 target debug connector with
MPC5xxx Nexus pinout.
Note: In practice, it has been noticed that 50-pin Samtec target connector does not provide good mechanical
stability in one direction which as a result can also yield electrically unreliable connection. Special care must be
taken when connecting this adapter to the target Samtec connector to minimize potential connection problems.
Note that no problems have been detected or reported in conjunction with the Mictor connector.
Jumper J2 (EVTIN)
Under some circumstances it can happen that the debugger cannot find any absolute program counter message in
the analyzed Nexus trace block. Consequentially, trace reconstruction fails and errors or nothing gets displayed
in the trace window. To avoid such situations, the debugger can feed periodic signal to the EVTIN CPU pin
connecting to the on-chip Nexus engine, which then periodically generates and broadcasts program counter
synchronization messages.
In order to use this feature, jumper J2 must be bridged and the ‘Force periodic Nexus SYNC’ option in the
‘Hardware/emulation Options/CPU Setup/Nexus’ tab must be checked. Refer to iSYSTEM ‘Freescale MPC5xxx
& ST SPC56 Family On-Chip Emulation’ technical notes document for more details on the ‘Force periodic
Nexus SYNC’ option use.
Note that the EVTI (Nexus Event In) CPU pin may be shared with other CPU functionalities. For instance, on
MPC5516 the same pin can operate as GPIO, EBI read/write or EVTI. Whenever the CPU pin is configured and
used for EVTI alternate operation, J2 must not be populated in order to prevent electrical conflicts..
Note: In general there is no need to use ‘Force periodic Nexus SYNC’ functionality unless a specific application
code is traced, which does not generate messages containing absolute program counter information. As long as
the user has no problems with the trace use, it is recommended to keep jumper 2 disconnected.