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CHAPTER 3 REGISTERS
3.3.2Byte Data Transfer and Operation of Accumulator (A) and Temporary Accumulator (T)
When data transfer to the accumulator (A) is performed
■Example of Operation of Accumulator (A) and Temporary Accumulator (T) in Byte Data Processing
An example of addition with carry of
MOV A, | 0042H | - |
MOV A, | 1280H | - |
ADDC A | - |
Figure 3.3-8 shows the operation of the accumulator and temporary accumulator when the above example is executed.
Figure 3.3-8 Operation of Accumulator and Temporary Accumulator in Byte Data Processing
Before execution | Last result |
AABXXH
TCDXXH
| RAM |
1280H |
|
56H | |
... |
|
| |
... | |
0042H |
|
EFH | |
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|
A | ABEFH | |
T | CDXXH | |
|
| RAM |
1280H | 56H | |
| ... | ... |
0042H | EFH |
A | AB56H | |
T | CDEFH *1 | |
|
| RAM |
1280H | 56H | |
| ... | ... |
0042H | EFH |
+ |
|
| A | AB*246H | ||
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CF | 1 |
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| T | CDEFH | |
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| RAM | ||
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1280H | 56H |
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| ... |
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... |
| ||
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0042H | EFH |
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*1 The TH does not change when there is automatic data transfer to the temporary accumulator. *2 The AH is not changed by the result of the addition of the AL, TL, and CF.
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