INSTRUCTION DESCRIPTIONS
A - 92 INSTRUCTION SET DETAILS MOTOROLA
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
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:
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
DO Start Hardware Loop DO
MR CCR
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
LF DM T ** S1 S0 I1 I0 SL EUNZ VC