Minimal custom arm m7 devloppement board designed as a 10 year anniversary present.
Selected MCU : STM32H750VBT6TR
MCU package : LQFP-100
Requirements :
-
SWD debug connected with pinout compatible with native 20 pin J-Link probe
-
Route all remaining mcu pins to female connectors
Schematic : schematics
Resulting pcb, front :
back :
SWD Connector Pinout:
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 | Vsupply | NC | This pin is not connected in J-Link. It is reserved for compatibility with other equipment. Connect to Vdd or leave open in target system. |
| 3 | Not used | NC | This pin is not used by J-Link. If the device may also be accessed via JTAG, this pin may be connected to nTRST, otherwise leave open. |
| 5 | Not used | NC | This pin is not used by J-Link. If the device may also be accessed via JTAG, this pin may be connected to TDI, otherwise leave open. |
| 7 | SWDIO | I/O | Single bi-directional data pin. |
| 9 | SWCLK | Output | Clock signal to target CPU. It is recommended that this pin is pulled to a defined state of the target board. Typically connected to TCK of target CPU. |
| 11 | Not used | NC | This pin is not used by J-Link. This pin is not used by J-Link when operating in SWD mode. If the device may also be accessed via JTAG, this pin may be connected to RTCK, otherwise leave open. |
| 13 | SWO | Input | Serial Wire Output trace port. (Optional, not required for SWD communication.) |
| 15 | 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. |
| 17 | Not used | NC | This pin is not connected in J-Link. |
| 19 | 5V-Supply | Output | This pin is used to supply power to some eval boards. |
Pins 4, 6, 8, 10, 12, 14, 16, 18, 20 are GND pins connected to GND in J-Link. They should also be connected to GND in the target system.
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