19-pin JTAG/SWD and Trace Connector
This article describes the 19-pin JTAG/SWD and Trace Connector, available on all J-Trace Pro.
Contents
Pinout
J-Trace provides a JTAG / SWD + Trace connector.
This connector is a 19-pin connector (0.05" / 1.27mm).
It connects to the target via an 1-1 cable.
The following table lists the J-Link / J-Trace SWD pinout.
PIN | SIGNAL | TYPE | Description |
---|---|---|---|
1 | VTref | Input | This is the target reference voltage. It is used to check if the target has power, to create the logic-level reference for the input comparators and to control the output logic levels to the target. It is normally fed from VDD of the target board and must not have a series resistor. |
2 | SWDIO / TMS | I/O / Output |
|
4 | SWCLK / TCK | Output |
|
6 | SWO / TDO | Input |
|
--- | --- | --- | This pin (normally pin 7) is not existent on the 19-pin JTAG/SWD and Trace connector. |
8 | NC / TDI | NC / Output |
|
9 | Not connected (TRST) | NC | By default, TRST is not connected, but the Cortex-M Adapter comes with a solder bridge (NR1) which allows TRST to be connected to pin 9 of the Cortex-M adapter. |
10 | nRESET | I/O | Target CPU reset signal. Typically connected to the RESET pin of the target CPU, which is typically called "nRST", "nRESET" or "RESET". This signal is an active low signal. |
11 | 5V-Supply | Output | This pin can be used to supply power to the target hardware. Older J-Links may not be able to supply power on this pin. For more information about how to enable/disable the power supply, please refer to Target power supply. If you do not plan to supply power to the target via this pin it is recommended to connect it to GND. |
12 | TRACECLK | Input | Input trace clock. Trace clock = 1/2 CPU clock in most cases. |
13 | 5V-Supply | Output | This pin can be used to supply power to the target hardware. Older J-Links may not be able to supply power on this pin. For more information about how to enable/disable the power supply, please refer to Target power supply. If you do not plan to supply power to the target via this pin it is recommended to connect it to GND. |
14 | TRACEDATA[0] | Input | Input Trace data pin 0. |
16 | TRACEDATA[1] | Input | Input Trace data pin 1. |
18 | TRACEDATA[2] | Input | Input Trace data pin 2. |
20 | TRACEDATA[3] | Input | Input Trace data pin 3. |
3, 5, 15, 17, 19 | GND | Ground | GND pins connected to GND in J-Link. They should also be connected to GND in the target system. |
Connecting the target board
J-Trace connects to the target board via a 19-pin trace cable. Alternatively J-Trace can be connected via the 20-pin J-Link Connector.