IAR Embedded Workbench for 8051

Complete development toolchain for 8051 providing one toolbox in one view, giving you one uninterrupted workflow.


User-friendly IDE

Integrated development environment with project management tools and editor. Included are configuration files and example projects for devices from many different manufacturers, run-time libraries with complete source code, linker and library tools, and a fully integrated static analysis with the add-on C-STAT.


Powerful build tools

IAR Embedded Workbench provides a highly optimizing C and C++ compiler for 8051. It includes a relocating 8051 assembler, support for DATA, IDATA, XDATA, PDATA and BDATA, support for multiple DPTR in compiler and libraries, bitwise addressing for SFRs and possibility to use up to 32 virtual registers.


Broad device support

IAR Embedded Workbench for 8051 provides support for many microcontroller devices. To enable a quick start, it includes configuration files, example projects and code templates for devices from many different manufacturers.


Comprehensive debugger

The C-SPY Debugger is a comprehensive debugger with an 8051 simulator. It has spport for RTOS-aware debugging on hardware and includes JTAG drivers, ROM-monitor as well as source code and project for creating your own ROM-monitor driver.


On-demand training included

When you buy a license of IAR Embedded Workbench for 8051, you get access to free training courses through our IAR Academy on Demand offering.

Latest releases

We are constantly updating and refining our tools with new features, new device support and extended capabilities.

Version 10.40


  • Support for changing the addresses for the B and IE registers
  • New option to place all code above bank zero for extended2 devices
  • Newer IDE version with many bug fixes
  • Updated IDE user guide and C-SPY debugging guide
Full release notes

Version 10.30

New device support

  • Silicon Labs: EFM8UB31F40G, EFM8UB30F40G
  • Texas Instruments: MSC1213Y2, MSC1213Y3, MSC1213Y4, MSC1213Y5, MSC1214Y2, MSC1214Y3, MSC1214Y4, MSC1214Y5

Improvement in C-STAT

Improved full report generation to reduce the risk of slowing down the IAR Embedded Workbench and/or external web-browser.

Read complete release notes

What type of license do you need?

IAR Embedded Workbench is available in a flexible license model to suit your company needs. Together with our support and update agreements, you get the support you need in multiple time zones and multiple languages. Send a request for quote or contact sales to get started.

Read more about Licenses

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User guides and documentation

Languages and standards

The IAR C/C++ compilers offer different dialects of the C and C++ programming languages, as well as different extensions specific for embedded programming (please note that not all language standards are supported for all target implementations). The compiler can be instructed to disable extensions for strict conformance to the standards. 

A wide range of industry-standard debug and image formats compatible with most popular debuggers and emulators are supported. This includes ELF/DWARF where applicable.

ISO/ANSI C/C++ Compliance

The IAR C/C++ compilers adhere to a freestanding implementation of the following C programming language standards:

  • INCITS/ISO/IEC 9899:2018, known as C18 (Latest version only).
  • The compiler supports all C++17 features. The C++ library supports C++14 with no C++17 additions.  (Latest version only).
  • ISO/IEC 14882:2015, known as C++14
  • INCITS/ISO/IEC 9899:2012, known as C11
  • ANSI X3.159-1989, known as C89

The ISO/ANSI C/C++ Compliance level varies between the different compilers. For complete information, please refer to the IAR C/C++ Compiler user documentation in your chosen product.

IEEE 754 standard

IAR Embedded Workbench supports the IEEE 754 standard for floating-point arithmetic.


MISRA C is a software development standard for the C programming language developed by MISRA, The Motor Industry Software Reliability Association. Its aims are to facilitate code safety, portability and reliability in the context of embedded systems, specifically those systems programmed in ISO C.

The first edition of the MISRA C standard, "Guidelines for the use of the C language in vehicle based software", was produced in 1998. In 2004, a second edition was produced with many substantial changes to the guidelines, including a complete renumbering of the rules. Additionally MISRA C:2012 with extended support and MISRA C++:2008 for identifying unsafe code constructs in the C++ standard have also been added to the standards.

IAR Embedded Workbench features an add-on product C-STAT so you can check compliance with rules as defined by MISRA C:2004, MISRA C++:2008 and MISRA C:2012.

Test validation

We use the following commercial test suites to test conformance of our tools to the standards:

  • Plum Hall Validation test suite for ISO/IEC C conformance
  • Perennial EC++ Validation Suite for C++ conformance
  • Dinkum C++ Proofer to test how our libraries conform to the C and C++ standard as well as test our STL implementation against the C++ standard.

In addition to the commercial suites, we use several in-house test suites for testing new features, regression testing, corrected errors, etc.

Hardware debugging support

NXP  Configurable IAR ROM-monitor for LPC935/LPC93xx
Analog Devices ROM-monitor for ADu83x/ADu84x, ADE51xx/ADE55xx and ADE71xx/ADE75xx devices
USB EA-Emulator
Texas Instruments USB/JTAG interface for 8051 based CC11xx, CC24xx and CC25xx SoC:s
8051 based Sensium devices
Configurable IAR ROM-monitor for MSC1211devices
Infineon Infineon Debug Access Server (DAS) for the Infineon XC8xx device family
Silicon Labs USB and serial (EC2) JTAG adapters supporting all C8051Fxxx devices
MIPS MIPS System Navigator Probe for 8051 Microcontroller Cores
Nordic Semiconductor nRF GO development platform (nRFProbe)
Nuvoton Nu-Link

3rd party plugins for C-SPY are also available for the following debug systems:

DoCD HAD Probe  supports devices based on the DX8051/DX80390 IP Core from Digital Core Designs
Phyton JEM52 supports debugging and programming for a variety of 8051 microcontrollers with on-chip debug interfaces
Phyton PICE52 real-time non-intrusive emulation of virtually all 8051 microcontrollers
Manley Electronics ME52HU and N-Link emulators
FlashPro-CC and GangPro-CC USB flash programming adapters for CCxxxx series Chipcon products from Texas Instruments by Elprotronic Inc.

A generic IAR ROM-monitor project template is included for configuration of additional 8051 boards and kits. We continuously add hardware debugging support for new devices. Please contact us to find out whether your new device is already supported or when it will become available.

Download free trial

IAR Embedded Workbench for 8051 - Free trial version

The evaluation license is free of charge and allows you to try the software for 14 days to evaluate its efficiency and ease of use. 

You will be asked to register to get your license when you click download.

Please note the following for the 14-day time-limited version:

  • Time limit for evaluation license is 14 days
  • Not allowed to be used for product development or any commercial use
  • Source code for runtime libraries is not included.
  • No support for MISRA C
  • Limited technical support

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