Why can only 256 bytes be moved from one address to another
in a MVC?




Answers were Sorted based on User's Feedback



Why can only 256 bytes be moved from one address to another in a MVC?..

Answer / mike m

THE LENGTH CODE FIELD IS 1 BYTE IN LENGTH.

THE LARGEST VALUE YOU MAY SPECIFY IN A 1 BYTE FIELD IS X'FF'

X'FF' = 255 DECIMAL

THE LEN. IN THE OBJECT CODE FIELD WILL BE 1 LESS THAN
ACTUAL LEN.

Is This Answer Correct ?    20 Yes 1 No

Why can only 256 bytes be moved from one address to another in a MVC?..

Answer / hariconda

MVC FORMAT: SS1 format

ASSEMBLER: OPCODE D1(L,B1),D2(B2)

here the length field is 8 bits or 1 byte so the maximum
value we can move is 256 bytes.

to move more than this use MVCL instruction

Is This Answer Correct ?    16 Yes 1 No

Why can only 256 bytes be moved from one address to another in a MVC?..

Answer / vikram

Lenght feild is 8 bits so the data is stored in binary
format so if we have all 8 bits set to 1 then the length
will be 128+64+32+16+8+4+2+1 = 255.or
2^7+ 2^6+2^5...2^0 = 255.

so the lenght is 256 .....

Is This Answer Correct ?    2 Yes 0 No




Why can only 256 bytes be moved from one address to another in a MVC?..

Answer / pazhanivel seethapathy

The length of MVC instruction is 1 Byte which is X'FF'. it
can have the range between 0 - 255 so totally 256 bytes of
data can be used.

Is This Answer Correct ?    2 Yes 1 No

Why can only 256 bytes be moved from one address to another in a MVC?..

Answer / roocarlin

the length of the MVC instruction itself is 6, one byte for the opcode, one byte for the length of the move-data, 2 bytes for base-displacement of the receiving field, and 2 bytes for the base-displacement of the sending field. since the length field in the MVC instruction is 1 byte, the values can be 0 to 255, thus you would be moving 1 to 256 bytes.

Is This Answer Correct ?    2 Yes 1 No

Why can only 256 bytes be moved from one address to another in a MVC?..

Answer / guest

the length of the MVC instruction is 256

Is This Answer Correct ?    1 Yes 11 No

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