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CHAPTER 2 BASICS OF SOFTWARE
DADDS
CY
←
0
Sign flag SFLAG
←
0
DADDS1
A
←
[DE] + [HL] + CY
Adds augend and addend with CY
Adjusts result to decimal
and stores in memory
DE
←
DE + 1, HL
←
HL + 1
Increments addend
and augend addresses
B
←
B – 1
B = 0
A
←
[DE] + [HL] + CY
Adds addend and augend with CY
Yes
CY = 1
Sign flag SFLAG
←
1
CY = 0
Yes
DADDS3
Result adjusted to decimal
CY = 1
No
Yes
No
A7 = 1
No
Yes
Sign flag SFLAG = 1
Yes
No
A7
←
1
Stores A to memory
RET
DADDS6
No
ERROR