Keil µVision AC5 to AC6

ARM Keil µVision: AC5 to AC6 Porting & Debugging Guide

This document summarizes the process of porting an ARM Keil µVision project from ARM Compiler 5 (AC5) to ARM Compiler 6 (AC6). Successful testing was completed on January 24, 2026.

---

1. Overview

• Target Hardware: STM32F103RCT6 based Self-balancing Robot Driver Board.
• Objective: Migrate to AC6 to avoid commercial license requirements associated with AC5.
• Key Result: Resolved the single-side motor rotation issue and established real-time debugging via ST-Link v2.

---

2. Porting Procedure (AC5 → AC6)

2.1 CMSIS and Environment Cleanup

• Delete Legacy Files: Remove system_stm32f10x.c, core_cm3.c, and startup_stm32f10x_hd.s from the existing CMSIS folder.
• Configure RTE: Navigate to Project > Manage > Run-Time Environment.
  • CMSIS > CORE: Select Version 5.5.0.
  • Device > Startup: Select the System Startup for STM32F1xx series.

2.2 Target Options Configuration

• Target Tab: Set the ARM Compiler to Version 6.
• Memory Settings: Ensure IROM1 is set to 0x8000000 (Size: 0x40000) and IRAM1 is set to 0x20000000 (Size: 0xC000).
• C/C++ (AC6) Tab:
  • Language C: c99.
  • Language C++: c++11.
  • Short enums/wchar: Enabled.
  • Optimization: Set to -O1.

---

3. Critical Code Modifications

3.1 motor.c (Fixing Motor Rotation)

A milestone fix to solve the issue where only one motor rotates after porting:

• Structure Initialization: Use memset to clear configuration structures (e.g., TIM_TimeBaseStructure) to zero, as this is mandatory for AC6 migration.
• PWM Output Enable: For advanced timers like TIM8, call TIM_CtrlPWMOutputs(TIM8, ENABLE) to set the MOE bit.

3.2 usart.c (Retargeting printf)

• Disable Semihosting: Add asm(".global __use_no_semihosting"); to avoid semihosting.
• fputc Modification: Redefine fputc to check USART_FLAG_TC (Transmission Complete) status for stable transmission in AC6.

---

4. Upload & Debugging

4.1 Uploading via FlyMcu

• Port Settings: FlyMcu typically recognizes COM1 to COM4; change the port in Device Manager if it exceeds this range.
• Options: Use 115200 bps and ensure ‘Verify’ and ‘Run After ISP complete’ are selected.

4.2 Real-time Debugging (ST-Link v2)

1. Define Symbol: Add DEBUG to the Preprocessor Symbols under Target Options.
2. External Power: Turn on the external power source.
3. Session: Click the Start/Stop Debug Session (d icon).
4. Verification: Set breakpoints in app_Bluetooth.c, run with F5, and verify Bluetooth data reception.