Mcu link SWD Debugging Issues

sw1234 — Thu, 04 Jan 2024 06:16:04 GMT

Hello.
I'm using the K32L2B21 series
I'm going to communicate with mcu link and mcu through SWD
On the circuit, the mcu is powered by an LDO of 1.8V (MCU supply power must be 1.8 V)

I understand that mcu link provides 3.3V power

I'm trying to do a swd debug, what should I do?

Thank you.

Re: Mcu link SWD Debugging Issues

xiangjun_rong — Thu, 11 Apr 2024 05:58:17 GMT

Hi,

Of course, the MCU-LINK device supports 1.8V logic, but you have change the default configuration on the MCU-LINK probe device.

1)R16 may be removed

2) SJ1 changed to connect to position 1-2

3)The pin1 of J6 must provide 1.8V voltage driven from target board as a reference voltage on the MCU-LINK probe board

Pls refer to section 5.1

5.1 Target operating voltage and connections
The MCU-Link Base Probe cannot power a target system, so uses a sensing circuit (see page 4 of the schematic) to detect the target supply voltage and set up level shifter voltages accordingly. It should not be necessary to make any modifications to this circuit, but there is a pull up resistor (33kΩ) to the 3.3V supply of the MCU-Link. If issues are seen with the target system supply being affected by the MCU-Link being connected then R16 may be removed and SJ1 changed to connect to position 1-2. This will fix the level shifters at the voltage level seen at pin 1 of the SWD connector, and require that the target supply can support the VCCB input requirements of the level shifter devices. It is not recommended to make these modifications until/unless the target system has been carefully checked to see that the correct reference/supply voltage is present on pin 1 of the SWD connector (J6).

i attach UM11931.pdf

Hope it can help you

XiangJun Rong

topic Mcu link SWD Debugging Issues in K32 L Series Microcontrollers

Mcu link SWD Debugging Issues

Re: Mcu link SWD Debugging Issues