Motorola 24-Bit Digital Signal Processor, DSP56000 manual END2, END1

INSTRUCTION DESCRIPTIONS

DO		Start Hardware Loop
Example:	:
DO #cnt1, END1		;begin outer DO loop
	:
DO #cnt2, END2		;begin inner DO loop
	:
	:
MOVE A,X:(R0)+
	:
END2		;last instruction in inner loop
ADD	A,B X:(R1)+,X0	;(in outer loop)
END1	:	;last instruction in outer loop
	:	;first instruction after outer loop

DO

Explanation of Example: This example illustrates a nested DO loop. The outer DO loop will be executed “cnt1” times while the inner DO loop will be executed (“cnt1” * “cnt2”) times. Note that the labels END1 and END2 are located at the first instruction past the end

of the DO loop, as mentioned above, and are nested properly.

Condition Codes:

15	14	13	12	11		10	9		8	7	6	5	4	3	2	1		0
LF	DM	T	**		S1	S0		I1	I0	S	L	E	U	N	Z		V	C
				MR									CCR

For source operand A or B:

LF — Set when a DO loop is in progress

S — Computed according to the definition. See Notes on page A-97.

L — Set if data limiting occurred. See Notes on page A-97.

For other source operands:

LF — Set when a DO loop is in progress

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