We've just updated MediaWiki and its underlying software. If anything doesn't look or work quite right, please mention it to us. --RanAS

MVP: Difference between revisions

From SnesLab
Jump to: navigation, search
(clobbered -> affected)
(linkify flags)
Line 18: Line 18:
!colspan="9"|Flags Affected
!colspan="9"|Flags Affected
|+
|+
|N
|[[Negative Flag|N]]
|V
|[[Overflow Flag|V]]
|M
|[[M Flag|M]]
|X
|[[X Flag|X]]
|D
|[[Decimal Flag|D]]
|I
|[[I Flag|I]]
|Z
|[[Zero Flag|Z]]
|C
|[[Carry Flag|C]]
|+
|+
|.
|.

Revision as of 04:08, 27 November 2023

Basic Info
Addressing Mode Opcode Length Speed
block move 44 3 bytes 7 cycles per byte moved
mvp.png
Flags Affected
N V M X D I Z C
. . . . . . . .

MVP (Block Move Positive) is a 65c816 instruction that copies a contiguous block of memory. It is intended to copy a block from a lower address to a higher address (moving it in the positive direction).

In Eyes & Lichty, the "P" in the mnemonic stands for "Previous" not "Positive."

Parameters

  • the X index register specifies the ending (highest) source address of the block
  • the Y index register specifies the ending (highest) destination address of the block
  • the C double accumulator specifies the length of the block in bytes minus one
  • the first operand byte specifies the destination bank the block will be in
  • the second operand byte specifies the source bank the block starts out in

Execution Sequence

The following loop is repeated until the value in the C double accumulator is $FFFF:

  • one byte is copied from the address in X to the address in Y
  • both X and Y are decremented
  • C is decremented

See Also

External Links