Motorola DSP56000 manual Address Register Indirect Postincrement, Postdecrement By Offset Nn

ADDRESSING

EXAMPLE: MOVE B0,Y: (R1)+

		BEFORE EXECUTION
	B2	B1				B0
55	48 47	24	23					0
A F			F E D C B A
7	0 23	0	23					0
			23	Y MEMORY				0
		$2501
			X	X	X	X	X	X
		$2500	X	X	X	X	X	X

150

R1 $2500

150

N1 XXXX

150

M1 $FFFF

Assembler Syntax: (Rn)+

Memory Spaces: P:, X:, Y:, XY:, L:

Additional Instruction Execution Time (Clocks): 0

Additional Effective Address Words: 0

			AFTER EXECUTION
	B2		B1	B0
55	48 47			24	23	0
A F		6 5 4 3 2 1			F E D C B A
7	0 23			0	23	0

Y MEMORY

	23						0
$2501	X X		X X		X	X	X
$2500	$	F E		D	C	B	A
			15				0
		R1			$2501
			15				0
		N1			XXXX
			15				0
	M1				$FFFF

Figure 4-5 Address Register Indirect — Postincrement

Rn without an associated data move.

4.4.1.5Postdecrement By Offset Nn

The address of the operand is in the address register, Rn (see Table 4-1and Figure 4-8). After the operand address is used, it is decremented by the contents of the Nn register and stored in the same address register. The contents of the Nn register are unchanged. This mode cannot be used for making XY: memory references, but it can be used to mod-

MOTOROLA ADDRESS GENERATION UNIT 4 - 11