Guidelines for the Use of the C Language in Vehicle Based Software MISRA is pleased to announce the publication of MISRA-C:2004.

We are pleased to announce that the work on revising MISRA C is complete and that Version 2 (to be known as MISRA-C:2004) was published on 14 October 2004.

Why update MISRA C?

Since its launch in 1998, the uptake and usage of MISRA C has far exceeded our expectations. MISRA C was originally developed to support the language requirements of the 1994 MISRA Guidelines, that specify the use of "a restricted subset of a standardized structured language" at SIL 2 and above in automotive applications. Since that time, however, MISRA C has been adopted and used across a wide variety of industries and applications including the rail, aerospace, military and medical sectors. Furthermore, a significant number of tools are available that support enforcing the MISRA C rules. In Japan, a Japanese translation of MISRA C has been published by JSAE, and the MISRA C Study Group have produced a book (in Japanese) giving detailed explanations of the rules and additional code examples.

We have received a considerable amount of feedback on MISRA C and recognized that a revision was appropriate, in particular to address the following:

• Ensuring that the language used is consistent with the standard language
• Replacing generalized rules for Undefined Behaviour with specific rules targeted at Undefined Behaviour only
• Ensuring "one rule, one issue"; i.e. complex rules are split into atomic rules for ease of compliance
• Adding to and improving the code examples
• Removing the option for tool-less use.

MISRA C launch events

The official launch of MISRA-C:2004 will be at the Embedded Systems Show at the NEC, Birmingham, UK on 13 October 2004. See The Embedded Systems Show for further details of the Show.

This will be followed by a MISRA C Technical Forum on 20 October - further details are available in the "Future forum meetings" section of this website.

At ESS, there will be an overview presentation from Gavin McCall of Visteon, who is chairman of the MISRA C Working Group. This will be followed by short presentations from the contributors and opportunities for questions.

The Technical Forum will provide in-depth tutorials on some of the new concepts in MISRA-C:2004, as well as the opportunity for further technical discussion.

MISRA-C:2004 FAQs

We expect a high level of interest in MISRA-C:2004 and we hope that the majority of the questions people have will be addressed in the following. Please note that during the launch phase we may not be able to respond to every question individually.

What has changed in MISRA-C:2004?

A number of the rules have been revised and the supporting text updated. Users of MISRA-C:1998 will also notice the following structural differences:

• The rules have been reorganized and renumbered.
• There are now 141 rules in total.
• A few rules from MISRA-C:1998 have been "rescinded" - this means that they do not have to be followed for MISRA-C:2004 compliance, but have been referenced in MISRA-C:2004 for backwards compatibility with MISRA-C:1998.

Is C99 covered?

MISRA-C:2004 is based on the C language as defined by ISO 9899:1990 (plus corrigenda). C99 has not been considered in MISRA-C:2004 due to the limited support for C99 on embedded microprocessors.

What formats is MISRA-C:2004 available in?

MISRA-C:2004 is simultaneously published as a paper document and as a PDF. PDFs will be customized to the individual purchaser and may not be placed on company intranets or similar services. A separate corporate PDF licensing mechanism will be available as before.

How can I purchase MISRA-C:2004?

All orders for individual copies will be handled through the new MISRA web store (see "Publications"). You will be able to pay for your purchase with a credit card through a secure transaction facility, and the document will be shipped or available for download typically within 3-5 working days. You will receive email notification of dispatch or availability for download. Please note all orders are subject to review hence the 3-5 days.

If you prefer not to use the web store, you will still be able to purchase directly from MIRA using a credit card, cheque in Pounds Sterling or company Purchase Order (subject to credit check) but we regret that once the web store is operational there will be a minimum transaction of GBP 100 for such purchases.

How much does MISRA-C:2004 cost?

The prices for MISRA-C:2004 are as follows. These prices are valid until 31 December 2004.

Document	UK	Europe	Other
"MISRA-C:2004 - Guidelines for the use of the C language in critical systems", hardcopy, each ISBN 0 9524156 2 3	£25	£35 EUR 55	£40 USD 70
"MISRA-C:2004 - Guidelines for the use of the C language in critical systems", single-user PDF ISBN 0 9524156 4 X	£10 + VAT	£10 + VAT	£10

Please note the following:

• Prices include dispatch.
• Hardcopy publications are zero-rated for VAT purposes but VAT is applicable to UK and EU sales for the PDF. VAT for EU sales to customers who supply a VAT number is the responsiblity of the customer and is not charged at point of sale. Warning this is based on our current understanding of VAT regulations, which may change at any time.
• UK VAT is currently charged at 17.5% and again this may change at any time.
• Approximate Euro and Dollar prices are shown for your convenience. All payments at the web store will be in Pounds Sterling.

I just bought MISRA-C:1998, am I entitled to an upgrade?

All orders for MISRA-C:1998 received at MIRA on or after 1 June 2004 and before 14 October 2004 will qualify the purchaser to obtain one free paper copy of MISRA-C:2004 per copy of MISRA-C:1998 purchased. To request a copy, you must quote the reference number from the packing note included with the document.

Only paper copies, not individual PDFs, of MISRA-C:2004 can be supplied under the terms of this offer. We regret that discounted bulk purchases do not qualify for this upgrade.

Corporate PDFs are also eligible for upgrades and rates are available on request.

Will MISRA-C:1998 be withdrawn from sale?

We recognize that a number of companies have major projects based on MISRA-C:1998 as a coding standard. Therefore copies will remain available for the foreseeable future.

Who was responsible for MISRA-C:2004?

The following organizations have contributed to the production of MISRA-C:2004:

• Hitex
• Keylevel Consultants
• Land-Rover
• LDRA
• Programming Research
• QinetiQ Malvern Technology Centre
• Ricardo Tarragon
• Visteon UK

The project management, publication and distribution have been handled by MIRA Ltd.

We also gratefully acknowledge all those that have contributed through the various reviews and consultations that have taken place. In particular we would like to recognize the contributions made by Society of Automotive Engineering (SAE) Embedded Software Task Force, Japanese Society of Automotive Engineers (JSAE), Japanese Automotive Manufacturers Association (JAMA) and Herstellerinitiative Software (HIS) Working Group (Arbeitskreis) "Software Test".