DOCUMENT:Q34375 04-MAY-2001 [masm] TITLE :DOCERR: Documentation Error on the LGDT Instruction PRODUCT :Microsoft Macro Assembler PROD/VER::5.1 OPER/SYS: KEYWORDS: ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Macro Assembler (MASM), version 5.1 ------------------------------------------------------------------------------- SUMMARY ======= The "Microsoft Macro Assembler 5.10 Reference Guide" states that the LGDT instruction only takes a memory 64 operand while the Intel manual states the LGDT instruction takes a memory 48 operand. The MASM Reference is incorrect. The correct operand size is memory 48. These instructions load essentially a 2-field structure whose total size is 48 bits. The first two bytes are the limit field and the last four bytes are the base field. This can be defined using the DF directive, or by defining a structure as described. Additional query words: 5.10 ====================================================================== Keywords : Technology : kbMASMsearch kbAudDeveloper kbMASM510 Version : :5.1 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.