Skip to main content

IAR Embedded Workbench for Arm 9.70.x

ST-LINK — Setup

In this section:

The Setup options specify the ST-LINK interface.

STLink_Setup_05_Arm.png
Emulator

Specify the emulator you are using. Choose between Auto (default) where the ST-LINK driver automatically selects the first emulator, or ST-LINK/V1, ST-LINK/V2 or ST-LINK/V3.

Serial no

If more than one debug probe is connected to the host computer, enter the serial number of the debug probe to identify the correct one.

Always prompt for probe selection

Makes C-SPY always ask you to confirm which probe to use, if more than one debug probe is connected to the host computer.

Reset

Selects the reset strategy to be used when the debugger starts. The actual reset strategy type number is specified for each available choice. Choose between:

System (0, default)

Resets the core and peripheral units by setting the SYSRESETREQ bit in the AIRCR register. Reset vector catch is used for stopping the CPU at the reset vector before the first instruction is executed. Only available for Cortex-M devices.

Hardware (1)

The probe toggles the nSRST/nRESET line on the JTAG connector to reset the device. This reset usually also resets the peripheral units. Only available for ST-LINK version 2.

Connect during reset (2)

ST-LINK connects to the target while keeping the reset pin active (the reset pin is pulled low and remains low while connecting to the target). Only available for ST-LINK version 2 and when debugging Cortex-M devices.

Core (3)

Resets the core via the VECTRESET (Cortex-M) or CWRR (Cortex-A) bit—the peripheral units are not affected.

Software reset (4)

Sets the PC to program entry address and SP to the initial stack pointer value.

Interface

Selects the communication interface between the ST-LINK debug probe and the target system. Choose between:

JTAG (default)

Uses the JTAG interface.

SWD

Uses fewer pins than JTAG.

Access port

Use this option to specify the access port when using devices with more than one core—shared mode debugging. Choose between:

Auto (default)

A predefined value for the device is used. For most devices, the access port defaults to 0.

Specify

For devices with more than one core, you can specify the number of the access port on the device you want to connect to, 0-3.

Target power

Select From the probe to specify that the supply voltage to your target device will be supplied by the probe. Use Target Vcc to specify the voltage.

Interfacespeed

Specify the JTAG and SWD communication speed. Choose between:

Default

Automatically uses the highest possible frequency for reliable operation. This is the only option for ST-LINK version 1.

n MHz

For ST-LINK version 2 and ST-LINK version 3, sets the JTAG and SWD communication speed to the selected frequency. This option is not available for ST-LINK version 1.

If the selected frequency is not supported by the specified probe, the closest and lowest supported frequency is automatically selected.

If there are JTAG communication problems or problems in writing to target memory (for example, during program download), these problems might be resolved if the speed is set to a lower frequency.