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Individual Instruction Descriptions
4-140
4.14.46 NEGAC Two’s Complement Negation of Accumulator
Syntax
[label] name dest, src [,mod]
Clock,
clk
Word,
w
With RPT,
clk
Class
NEGAC A
n
[~], A
n
[~] [,
next A
] n
S
+3 1 n
R
+3 3
Execution [premodify AP if
mod
specified]
dest
⇐ –
src
PC ⇐ PC + 1
Flags Affected OF, SF, ZF, CF are set accordingly
Opcode
Instructions 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
NEGAC A
n
[~], A
n
[~] [,
next A
] 1 1 1 0 0
next A
A
n
0 0 0 0 0 0 A~ ~A
Description Perform two’s complement negation of
src
accumulator and store result in
dest
accumulator.
See Also NEGACS, SUB, SUBB, SUBS, ADD, ADDB, ADDS, NOTAC, NOTACS
Example 4.14.46.1 NEGAC A3~, A3, ––A
Predecrement accumulator pointer AP3. Negate accumulator A3 and store result in accumulator A3~.