STM32H563 Multi-Controller Architecture – CPU & Memory Margin

[Ibrahimsha]

Hello ST Community,

I am working on an industrial combo vending machine controller system and would like to request a design review / best-practice feedback for an architecture based on STM32H563ZIT6.

I have attached two reference documents for clarity:

1. System Architecture Document, describing the multi-controller design (Main, Stepper, and DC Load controllers), and

2. CPU Load & Memory Utilization Analysis, providing a theoretical and worst-case analysis of CPU load and memory margins.

System Overview

• MCU: STM32H563ZIT6 @ 200 MHz

• Operation: Industrial application, 24×7 continuous operation

Architecture:

• Main / Process Controller

• Stepper Motor Controller

• DC Load Controller

Each controller uses a dedicated STM32 MCU to separate process logic, real-time motor control, and power load handling.

---

1. Main Controller – CPU Load & Memory Utilization

• Multiple interrupt sources (flow sensors, actuator pulses, PWM capture)

• UART RS485 communication @ 115200

• ADC usage with DMA

• Continuous vs process-based CPU load classification

• Worst-case CPU utilization < 20% (**Please check our attached Doc)

• RAM usage ~4.4%, Flash usage ~4% (Build Analyzer)

Question:
From STM best-practice perspective, is this CPU and memory margin considered sufficient for long-term industrial operation?

---

2. Stepper Controller Design

• MCU: STM32H563ZIT6

• Stepper driver: DRV8711

• SPI topology under consideration:

  • Single SPI bus with multiple chip-selects

  • Versus multiple SPI buses

Question:
Is a single SPI bus with multiple CS or Multiple SPI bus with Multiple CS an acceptable and recommended approach for this type of application?

---

Objective

• Validate MCU selection

• Confirm CPU and memory margins

• Align the design with STM recommended best practices for industrial systems

Any feedback or guidance from ST engineers or experienced users would be greatly appreciated.

Thank you.

[mƎALLEm]

Hello,

1- I'm wondering about the document confidentiality of the first attachment. It's marked as a confidential document. Are you sure to share that in public?

2- The CPU load / memory size depends on your tests and your application we cannot confirm if STM32H563 is 100% suitable for your application. You need to run some tests and make your assessment.