Issues generating correct PWM duty cycle using matlab STM32 Coder on NUCLEO-G474RE (TIM1 Advanced Timer)

Hi everyone,

I’m running into a confusing issue while using MATLAB STM32 Coder with a NUCLEO-G474RE and wanted to check if anyone here has faced something similar.

What I’m trying to do:

• Generate a fixed-frequency PWM with variable duty cycle
• Using Advanced Timer TIM1
• Duty cycle driven from Simulink (percentage input)
• Target hardware: STM32G474RE (NUCLEO board)
• MATLAB R2025a, ARM GNU Toolchain

Setup details:

• Using the PWM Output block from STM32 Support Package
• Timer module: TIM1
• Duty cycle unit: Percentage
• Only Channel 1 enabled
• Timer group set to Advanced Timers 1/8/20
• Timer configured to start during model initialization
• No interrupts enabled
• Pins configured correctly in CubeMX and verified to be in AF (Alternate Function) mode
• Same pin/timer configuration works as expected when using CubeMX + HAL code directly

The problem:

Although the PWM signal is present on the expected pin, the duty cycle does not match the input value from Simulink.

• Example: 50% input does not give a clean 50% duty cycle, it instead defaults to the pulse value given in the cubemx file.
• Changing the input does not scale the duty as expected
• Behavior feels like either:
• CCR registers aren’t updating correctly, or
• MOE / output enable / complementary settings are interfering, or
• MATLAB’s abstraction of TIM1 differs from CubeMX behavior

Things I’ve already checked:

• Correct pin mapping for TIM1_CH1
• AF mode confirmed
• No dead-time or break inputs enabled
• No complementary outputs enabled
• Clock configuration looks fine
• Timer counter is running

I’ve attached screenshots of my PWM block configuration and Hardware Implementation Timers (TIM1) settings for reference.

Any insights, would be really appreciated

Thanks!

Answer 1

[Swaroop Gopa Srinivas]

• Make sure to set the sample time of constant block.

• Below are the settings in cubeMX file to generate signal with the period of 1ms

• I was able to generate the expected signal. In the below external mode simulation, I changed duty cycle from 50% to 80%. It worked fine.

[Anmol Govindarajapuram]

Thank you this did work. Additionally this was fixed by creating a new file, another way was configuring a general purpose timer and then confgiruing the advance timer!!!