Move Words and Clear (MVC)/OP=13

Format

OP AF BF A Syllable B Syllable

OP = 13

AFBF length of both operands. A value of 0000 is equal to a length of 10,000 4-digit words or 40,000 digits. AF or BF may be indirect. A literal flag will cause an Invalid Instruction (IEX = 21) fault. See Compatibility Notes A.07.1.

The A Syllable is the address of the source data field. Address may be indexed, indirect or extended. Final address controllers are ignored.
The B Syllable is the address of the destination data field. Address may be indexed, indirect or extended. Final address controllers are ignored.

Note

Use of addresses which are not congruent to zero modulo 4 may produce incompatible results (see Compatibility Notes A.07.2.

Function

The Move Words and Clear instruction moves the number of four digit words specified by the concatenation of AF and BF from the source data field in memory to the destination data field in memory.

The contents of the source data field are set to zero.

Comparison Flags

The Comparison Flags are unchanged by this instruction.

Overlap

When the final B address is less than the final A address and the fields partially overlap, the source data field will be shifted by that number of digits to the left.

When the B data field partially overlaps the A data field and B is greater than A, the data from the A address to the B address will be right justified in the destination data field and filled with leading zeros.

When the B data field totally overlaps the A data field, the A data field will is rewritten but not cleared.

Examples

Example (1) Move eight digits and clear the source field

OP AFBF A Syllable B Syllable
13 0002 A Field B Field
                    BEFORE              AFTER
   A Field         F1F2F3F4          00000000
   B Field         nnnnnnnn          F1F2F3F4
   Comparison Flags   nn            unchanged
   Overflow Flag      nn            unchanged

Example (2) Justify data field

OP AFBF A Syllable B Syllable
l3 0002 A Field A Field + 4
                    BEFORE              AFTER
   A Field        1605nnnnnnnn      000000001605
   Comparison Flags   nn              unchanged
   Overflow Flag      nn              unchanged
instructions/mvc.txt · Last modified: 2008/05/13 07:22 (external edit)
 
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