Adaptation for NEXUS MPC5XXX

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Adaption for NEXUS on MICTOR 38 / GLENAIR 51 / SAMTEC 50 / SAMTEC 20

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Adaption for NEXUS on MICTOR 38 / GLENAIR 51 / SAMTEC 50 / SAMTEC 20

Trace connectors for MPC55XX/56XX

General Signal recommendation and information

  • TDI, TDO, TCK, TMS and JCOMP should be connected directly to the CPU. Don't connect serial resistors or RC combinations to the lines.

  • Avoid routing the JTAG signals close to the NEXUS signals.

  • VTREF can be connected directly to target VDD, or optional with a serial resistor with 1kOhm or less
  • Input impedance on VTREF:
    • LA-7630: >30 kOhm
    • LA-7610: >20 kOhm

  • When the debugger is inactive (SYStem.Mode.DOWN and NoDebug), all output pins are tri-stated (hot-plug capability)

  • During the debug session: TDI, TCK, TMS and JCOMP- are driven to both low and high levels. The voltage level of a pin driven to high is the same voltage level as connected to VDD target (pin 11).

  • RSTIN is an open-drain output. RSTIN and RSTOUT support a voltage level of max 5V, independent of VDD target.

  • All input output signals of the preprocessor have a 10 Ohm serial termination. Usually no further termination is needed on the target hardware.

  • The RDY- signal is optional.
    If the signal is not available, or can not be connected because of other reasons, the RDY- pin on the debug connector should be connected to GND.
    If the RDY- signal on the debug connector is not connected, set SYStem.Option.NOJTAGRDY ON.

  • If the signal JCOMP is not available on the used processor/package type, leave the JCOMP pin on the debug connector unconnected.

  • The signal CLKOUT is not required for debugging or tracing. It is recommended to leave the pin unconnected. On the Nexus adapter, the signal is terminated and also connected to an input buffer.
Trace connectors for MPC55XX/56XX
Mictor 38-pin GlenAir 51-pin SAMTEC 50-pin SAMTEC 20-pin                                                                               

Connector Mictor 38-pin (Debug + Trace signals)





Connect Pin 39,40,41,42 and 43 to GND

Signal recommendations for Mictor 38-pin

  • Signal TDET/WDTC (pin 27, TOOLIO2) is used to detect another development tool connected to the debug port (ETK, GSI). In order to let the debugger automatically detect the development tool, connect this signal with 10K to GND on the target.

  • Signal TDET/WDTC can also be used to disable a watchdog on the target. Enable this signal using TrOnchip.TOOLIO2. Also in this case, connect this signal with 10K to GND on the target.

  • Signals BGRNT (29) and BREQ (35) are reserved for inter-tool communication and should be left open on the target, if the debugger is the only tool connected to the target.

  • If the trigger signals EVTI and EVTO are disabled (TrOnchip.EVTEN OFF) and the pins are used for other functions, do not connect these signals to the trace connector.

  • If available, connect RSTOUT to pin 25. The debugger can use this signal to detect target resets.
    When connected, set SYStem.Option.RSTOUT ON.

Information about MDO16 Operation:

  • For processors with 16 MDO signals, connect MDO[12..15] to mictor pins 1..4 (not defined in the NEXUS standard).

  • NEXUS AutoFocus Adapter LA-7630 with Mictor-38 Converter (LA-7631): Jumpers J100..J103 must be closed using Zero-Ohm resistors. Doing so will connecxt MDO12..15 to the NEXUS adapter. If resistors are placed, make sure that pins 1..4 are used for MDO12..15. If not used or not provided by the processor, leave pins N/C. Any other signals on these pins could lead to damage of the NEXUS AutoFocus Adapter.

  • Older NEXUS Adapters (LA-7610, LA-7611): Leave pins 1..4 N/C. MDO16 mode is not supported by older NEXUS adapters.

  • Although both Mictor-38 and Samtec-50 connectors are supported, it is recommended to use Samtec-50 for all processors with 16 MDO signals.

Target Connector description and layout

Mictor 38-pin

Order No

TE Connectivity part numbers for suitable receptacles (for target)

TE 2-5767004-2 RoHS compliant
TE 2-767004-2
TE 767054-1 (suggested by Motorola)
TE 767061-1
TE 767044-1 : Board-to-Board Type: Coplanar

TE Connectivity


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Last generated/modified: 07-Mar-2024