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ADC: Difference between revisions
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|2 cycles* | |2 cycles* | ||
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After ADC runs, the [[carry flag]] will indicate whether the addition caused an unsigned overflow. The [[zero flag]] will be set if the sum is zero and cleared otherwise. | After ADC runs, the [[carry flag]] will indicate whether the addition caused an unsigned overflow. The [[zero flag]] will be set if the sum is zero and cleared otherwise. | ||
If the [[decimal flag]] is set, then [[binary coded decimal]] addition is performed, otherwise binary addition. | |||
==== Syntax ==== | |||
<pre> | |||
ADC #const | |||
ADC addr | |||
ADC long | |||
ADC dp | |||
ADC (dp) | |||
ADC [dp] | |||
ADC addr, X | |||
ADC long, X | |||
ADC addr, Y | |||
ADC dp, X | |||
ADC (dp, X) | |||
ADC (dp), Y | |||
ADC [dp], Y | |||
ADC sr, S | |||
ADC (sr, S), Y | |||
</pre> | |||
=== See Also === | === See Also === | ||
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* [[ADC (SPC700)]] | * [[ADC (SPC700)]] | ||
* [[ADC (Super FX)]] | * [[ADC (Super FX)]] | ||
* [[ADD (Super FX)]] | |||
=== External Links === | === External Links === | ||
Latest revision as of 22:59, 6 July 2024
| Basic Info | |||||||
|---|---|---|---|---|---|---|---|
| Addressing Mode | Opcode | Length | Speed | ||||
| Immediate | 69 | 2/3 bytes | 2 cycles* | ||||
| Absolute | 6D | 3 bytes | 4 cycles* | ||||
| Absolute Long | 6F | 4 bytes | 5 cycles* | ||||
| Direct Page | 65 | 2 bytes | 3 cycles* | ||||
| Direct Page Indirect | 72 | 2 bytes | 5 cycles* | ||||
| Direct Page Indirect Long | 67 | 2 bytes | 6 cycles* | ||||
| Absolute Indexed by X | 7D | 3 bytes | 4 cycles* | ||||
| Absolute Long Indexed by X | 7F | 4 bytes | 5 cycles* | ||||
| Absolute Indexed by Y | 79 | 3 bytes | 4 cycles* | ||||
| Direct Page Indexed by X | 75 | 2 bytes | 4 cycles* | ||||
| Direct Page Indexed Indirect by X | 61 | 2 bytes | 6 cycles* | ||||
| Direct Page Indirect Indexed by Y | 71 | 2 bytes | 5 cycles* | ||||
| Direct Page Indirect Long Indexed by Y | 77 | 2 bytes | 6 cycles* | ||||
| Stack Relative | 63 | 2 bytes | 4 cycles* | ||||
| Stack Relative Indirect Indexed by Y | 73 | 2 bytes | 7 cycles* | ||||
| Flags Affected | ||||||||
|---|---|---|---|---|---|---|---|---|
| N | V | M | X | D | I | Z | C | |
| . | . | . | . | |||||
ADC (Add with Carry) is 65x instruction that performs an addition. As there is no add-without-carry instruction, a CLC should be run (or the carry flag otherwise ensured to be clear) before an ADC, or else the sum will be one greater than expected.
The sum is stored in the accumulator.
After ADC runs, the carry flag will indicate whether the addition caused an unsigned overflow. The zero flag will be set if the sum is zero and cleared otherwise.
If the decimal flag is set, then binary coded decimal addition is performed, otherwise binary addition.
Syntax
ADC #const ADC addr ADC long ADC dp ADC (dp) ADC [dp] ADC addr, X ADC long, X ADC addr, Y ADC dp, X ADC (dp, X) ADC (dp), Y ADC [dp], Y ADC sr, S ADC (sr, S), Y
See Also
External Links
- Eyes & Lichty page 423, on ADC: https://archive.org/details/0893037893ProgrammingThe65816/page/n449
- Labiak page 115 on ADC: https://archive.org/details/Programming_the_65816/page/n125
- MCS6500 Manual page 7 on ADC: https://archive.org/details/mos_microcomputers_programming_manual/page/n22
- https://archive.org/details/mos_microcomputers_programming_manual/page/n204, lbid.
- Carr page 245 on ADC: https://archive.org/details/6502UsersManual/page/n258
- Leventhal page 3-38 on ADC: https://archive.org/details/6502-assembly-language-programming/page/n87
- undisbeliever on ADC: https://undisbeliever.net/snesdev/65816-opcodes.html#adc-add-with-carry