Labels:box | bulletin board | shelf | sky | slide projector OCR: DF Memory DS 2000 20000 20001 20002 Destination 0002 block 2000 Source 2000 block 20004 20005 20006 0000 20007 0005 Memory 00000 DS 2000 20001 20002 Destination 0007 block Source 20003 block 20004 2000 20005 20006 0005 20007 0000 FIGURE 11.2 When overlapping blocks are the source and destination for rep movsb the direction in which the copy must proceed depends on the direction of overlap In this figure the source block starts at a higher address than the destination block, So the copy must proceed from lower addresses to higher addresses. This is the mode of operation of the string instruc tions when DF is equal to 0 as it normally is. A) The state of the PC before rep movsb executed to copy such an overl lapping block. (B) The state of the PC after the is completed 0000Z 0006 normall cxe ...
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