ARM Register Bitfield Visualizer - Interactive Register Debug Tool

Visualize and manipulate ARM register bitfields interactively. Parse register definitions from header files, set individual bits, view masks and values. Perfect for debugging STM32, Cortex-M, and other ARM peripheral configurations.

Add Bitfield

Register Visualization (32-bit)

Hexadecimal:
0x00000000
Decimal:
0
Binary:
0b00000000000000000000000000000000

Defined Bitfields

No bitfields defined. Add fields manually or parse from header.

About ARM Register Bitfield Visualizer

A powerful tool for ARM embedded developers to visualize and manipulate register bitfields interactively. Perfect for debugging peripheral configurations on STM32, Cortex-M, and other ARM microcontrollers without needing an IDE or debugger.

Features:

  • Visual 32-bit register representation
  • Click individual bits to toggle them
  • Parse register definitions from C header files (STM32 style)
  • Manual bitfield entry with start/end bit positions
  • Real-time hex, decimal, and binary value display
  • Set register value from hex, decimal, or binary input
  • Color-coded bitfield visualization
  • Tooltips showing field names and descriptions
  • Calculate masks and field values automatically
  • Common ARM peripheral presets (RCC, GPIO, SCB, etc.)
  • Copy values to clipboard
  • Export/import register configurations

How to Use:

  • Manual Entry: Add bitfields by specifying name, bit range, and description
  • Parse Header: Paste register definitions from STM32 or CMSIS header files
  • Presets: Load common ARM peripheral registers (STM32, Cortex-M)
  • Click Bits: Click on any bit in the visualization to toggle it
  • Set Value: Enter hex (0x1234), decimal (4660), or binary (0b...) to set register

Supported Header Formats:

#define REG_FIELD_Pos (16U) #define REG_FIELD_Msk (0x1UL << REG_FIELD_Pos) #define REG_FIELD REG_FIELD_Msk

Common Use Cases:

  • Debugging Peripherals: Visualize register configurations during development
  • Learning ARM Architecture: Understand how bits map to hardware features
  • Code Review: Verify register initialization values
  • Documentation: Create visual register diagrams for documentation
  • Quick Calculations: Calculate bitmasks and field values without IDE
  • Hardware Bring-up: Test register configurations before writing to hardware

Tips:

  • Copy register definitions directly from vendor header files (e.g., stm32f4xx.h)
  • Use the preset library for common STM32 and Cortex-M registers
  • Hover over bitfields to see detailed information
  • Click individual bits for fine-grained control
  • Use the "Set Value" feature to load register values from debugger