1 Introduction

1.1 Purpose of the Document

Help developers and ODM be attentive to and comprehend the built-in MCU functions, including self-calibration, that are essential for models during the development and testing phases.

1.2 Overview of MCU Development

1.2.1 Types

Two types for different display models

MCU on color sensor module
MCU on motherboard (CVD projects only)

1.2.2 MCU main functions

MCU firmware upgrade
Motor and sensor control
Self-calibration (manual and auto)
Auto execution by appoitment and periodically
Factory reset
Communication with scaler
Error detection and error message sending

1.2.3 Block Diagram

1.3 Scope and Objectives

Ensure information of ASUS and ODMs are synchronized

1.3.1 Color sensor module models

PA32UCXR
PA24US

1.3.2 MCU on motherboard models

PA32DC
PA27DCE
MH3281A
HA3281A

# 2 Hardware Requirement ## 2.1 Microcontroller * With Silicon Labs MCU EFM32LG990F256G on mothorboard or color sensor module. * Cable and connector for debug board.

2.2 Peripheral Connections

MCU firmware debug board: Silcon Labs EFM32 Leopard Gecko Starter Kit (STK, ex. EFM32LG-STK3600)

STK cables and connectors for computer and color sensor module.

3 Firmware Development

3.1 Development Environment Setup

Silicom Labs IDE (Integrated Development Environment) Simplicity Studio (https://www.silabs.com/developers/simplicity-studio)
Compiler and Toolchain
Silicom Labs STK debug board (only for CVD and ASUS developers)

3.2 GPIO functions

There are three input pins, a ouptput pin and a test pin used in MCU flow as the table.

Definition	Description	Pin	Input/Output
Scaler_INFO	Scaler inform MCU scaler event is triggered	PD1	Input
FW_UPGRADE	Scaler inform MCU to upgrade	PD2	Input
MCU_INFO	Ouput high if MCU is in AP mode	PD3	Output
PSU_ON	Scaler inform MCU to enter sleep mode	PC13/PC15	Input
TP9	MCU testing pin	PC3	Input/Output

The PSU_ON is PC13 in color sensor board and defined as PC15 in MCU on motherboard projects.
The TP9 is a test pin.

3.2.1 Input pins

MCU will polling these pins in main loop and will be wake up if the interrupt triggered by scaler.

Definition	Pin	Active	Polling (ms)	Interrupt trigger	MCU Board
Scaler_INFO	PD1	Low	1	N/A	Both
FW_UPGRADE	PD2	Low	100	N/A	Both
PSU_ON	PC13	High	1000	Falling edge	For MCU on color sensor board
PSU_ON	PC15	Low	1000	Rising edge	For MCU on motherboard

3.2.2 Output Pin

The pin MCU_INFO (PD3) will be high if MCU running in AP code.

3.2.2 Test Pin

The pin TP9 (PC3) is a test pin which can be set input or output for testing and debugging.

3.2.3 GPIO Interrupt Handler

Interrupt routines are defined in system_emf32lg.h and this project use PSU_ON in GPIO_ODD_IRQHandler only.

3.3 MCU Flows

3.3.1 Firmware upgrade flow

3.3.1.1 MCU bootloader version is B01T00 or later.

3.3.1.2 MCU bootloader version is B00TXX.

3.3.2 All reset flow

All reset function will clear the user mode preset data and restore all registers to factory state. Scaler wiil enter flash reboot and pop-up a message box for power saving mode selection.

3.3.2 Main flow

All reset function will clear the user mode preset data and restore all registers to factory state. Scaler wiil enter flash reboot and pop-up a message box for power saving mode selection.

3.3.3 Self-Calibrarion flow

3.4 Initialization

3.4.1 GPIO

MCU_info
Sleep_pin

3.4.2 Backup real time clock

3.4.3 Motor and sensor

3.5 Communications

MCU commnicate with scaler by I2C and GPIO

3.5.1 Scaler event

3.5.2 MCU event

3.5.3 Flash reboot

3.5.4 Sleep and wake

3.6 Power Management

(1) Low Power Modes

Energy mode 3
Backup mode

(2) Sleep and Wakeup Strategies

Power saving mode
- Normal-sleep
- Deep-sleep
- DC-Off
Wake-up event
- Self-calibration appointment setting
- GPIO
- Burtc camparsion

8. Error Handling and Fault Tolerance

(1) Exception Handling

8. Security Considerations

(1) Encryption and Authentication

(2) Secure Boot (if applicable)

IV. Integration and Testing

1. MCU and Hardware Integration

(1) Connection of MCU with Peripherals

(2) System Integration

2. Software Integration

(1) Firmware upgrade

USB flash drive:
Scaler bin file: MODELNAME.bin
MCU bin file: MODELNAME_M.bin
Text file: binfname.txt ( Text content should be MODELNAME_M.bin ) Example: Model Name PA32XXX
- PA32XXX.bin for Scaler
- PA32XXX_M.bin for MCU
- binfname.txt (Text content is PA32XXX_M.bin)
- Press the two buttons simultaneously for 3 seconds

(2) Functional Testing

Input source:
- Yes : auto or manual execution
- No : auto execution only

Power saving mode:

Power saving - normal level (1). MCU enter normal sleep mode
MCU awake as the appointment time up
MCU enter auto execution and start self-calibration
MCU enter normal sleep mode again after all targets self-calibration accomplished

Power saving - deep level

MCU will enter DC-off after all targets self-calibration accomplished DC off : MCU will enter energy mode

         Back to DC-off after all targets self-calibration accomplished
    AC off :
     MCUwill enter backup mode 
     AC 
     
     (1)	Normal-sleep
     (2)	Deep-sleep
     (3)	DC-off
     (4)	AC-off => AC-on => normal-sleep/deep-sleep (AC-off 期間無交集到預約時間)
     (5)	AC-off => AC-on => normal-sleep/deep-sleep ((AC-off期間有交集到預約時間)

3. Performance Testing
    (1) Benchmarking
    (2) Stress Testing
4. Validation and Verification
    (1) Compliance Testing
    (2) Regulatory Testing (if applicable)

Error code:

Troubleshooting:

V. Documentation

1. Hardware Documentation
    (1) Schematics
    (2) PCB Layout
2. Firmware/Software Documentation
    (1) Code Comments
    (2) API Documentation
3. User Manual
    (1) MCU Features
    (2) Troubleshooting Guide

VI. Conclusion

1. Summary of Achievements
2. Lessons Learned
3. Recommendations for Future Development

This outline provides a structured approach to documenting the MCU development process for ODM, covering both hardware and firmware/software aspects. Depending on the specific requirements of your project, you may need to adjust and expand each section accordingly.