SPRACK9 February 2019 AM1705 , AM1707 , AM1806 , AM1808 , OMAP-L132 , OMAP-L137 , OMAP-L138 , TMS320C6742 , TMS320C6745 , TMS320C6746 , TMS320C6747 , TMS320C6748
This checklist can be applied to any XDS connector for both JTAG and Trace applications.
| PIN | XDS SignalType (1) | Target Signal Type | NAME | CHECKLIST ITEMS |
|---|---|---|---|---|
| TRST | O | I | Test Logic Reset | TRST- should normally be pulled down on the target card. This holds the device's JTAG/debug logic in reset when an XDS cable is not present. For all cases, this is the normal operating mode of the device. If a device does not have a TRST pin then the pin on the connector can be left disconnected. TI recommends a 4.7K pull-down but common values in the 4.7K to 10K range are acceptable. |
| TCK | O | I | Test Clock | The requirements for TCK are dependent on the number of devices in the JTAG serial chain and on the routing distance of the TCK signal.
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| TMS | O | I | Test Mode Select | The requirements for TMS are dependent on the number of devices in the JTAG serial chain and on the TMS signal routing distance.
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| TDI | O | I | Test Data Input | The requirements for TDI are dependent on the number of devices in the JTAG serial chain and on the TDI signal routing distance.
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| TDO | I | O | Test Data Output | The requirements for TDO are dependent on the number of devices in the JTAG serial chain and on the TDO signal routing distance.
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| RTCK | I | O | TCK Return | The requirements for TCK are dependent on the number of devices in the JTAG serial chain, on the routing distance of the TCK signal, and if the device supports a RTCK pin.
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The following signals may also be present on your XDS Target Cable and are common to many XDS products.
| PIN | XDS Signal Type | Target Signal Type | NAME | DESCRIPTION |
|---|---|---|---|---|
| TVRef (1) | I | O | Target Voltage Reference | Must be tied to the I/O voltage of the target device used for JTAG through a 100 Ω current limiting resistor. Used by the XDS to detect if power is active and to set JTAG signal voltage level translators (if supported by the XDS(1). |
| TDIS | I | O | Target Disconnect | If your XDS connector supports this signal it must be tied directly to the target's ground plane. Connecting it through a pull-down resistor may cause the XDS to NOT detect the target system and prevent normal operation. |
| EMU[0:n] | I/O | I/O | Emulation Port | EMU0 and EMU1 must be pulled-up on the target card. For EMU0 and EMU1, it is not recommended relying on the internal pull-ups normally provided in most devices on the EMU pins. It is recommended to connect all the XDS pins supported by your device to the XDS connector. In cases where you are connecting more than EMU0 and EMU1, follow the instructions in the Emulation and Trace Headers Technical Reference Manual. In cases where the device supports more than two EMU pins, these devices normally support high speed trace (either Core Trace, System Trace or both) in which case it is a requirement to utilize termination resistors per Emulation and Trace Headers Technical Reference Manual. In cases where the device has more EMU pins than the XDS supports, the general rule is to connect as many EMU signals as possible to the XDS connector. For some device families, due to packaging size limitations, EMU signals are being multiplexed with other device functional signals on a single pin. If you are not using the functional signal then simply connect the pin to the XDS connector per the instructions in the previous paragraph. If you need both the functional and EMU (trace) capabilities then TI recommends you isolate the XDS header and functional circuit from each other using a FET mux. |
| nRESET (2) | O | I | Target Reset | This is an optional signal that if integrated into your application's power-up-reset circuit may be used to remotely reset the target board. This signal driven from the XDS (if supported) is open-drain and therefore requires a pull-up. |