September 1993Order Number� 270251-004MCS� 51 Family ofMicrocontrollersArchitectural OverviewInformation in this document is provided in connection with Intel products� Intel assumes no liability whatsoev-er� including infringement of any patent or copyright� for sale and use of Intel products except as provided inIntel’s Terms and Conditions of Sale for such products�Intel retains the right to make changes to these specifications at any time� without notice� MicrocomputerProducts may have minor variations to this specification known as errata��Other brands and names are the property of their respective owners��Since publication of documents referenced in this document� registration of the Pentium� OverDrive andiCOMP trademarks has been issued to Intel Corporation�Contact your local Intel sales office or your distributor to obtain the latest specifications before placing yourproduct order�Copies of documents which have an ordering number and are referenced in this document� or other Intelliterature� may be obtained from�Intel CorporationP�O� Box 7641Mt� Prospect� IL 60056-7641or call 1-800-879-4683COPYRIGHT � INTEL CORPORATION� 1996MCS�-51 Family of MicrocontrollersArchitectural OverviewCONTENTSPAGEINTRODUCTION ��������������������������� 1CHMOS Devices ��������������������������� 2MEMORY ORGANIZATION IN MCS�-51DEVICES �������������������������������� 2Logical Separation of Program and DataMemory ���������������������������������� 2Program Memory ��������������������������� 3Data Memory ������������������������������ 4THE MCS�-51 INSTRUCTION SET �������� 5Program Status ...
