... | ... | @@ -12,6 +12,52 @@ PC + 0 7 8 9 C D F 10 |
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```
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NOTE: Not all instructions will use every part of the above diagram. For example, a byte-sized operand will consume one byte instead of two, and some instructions may use zero or one operand.
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## AMOD Byte
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In the ILXIM architecture, the AMOD (Addressing MODe) byte describes the semantic interpretation of the following operand. It contains three fields: type, mode, and displacement.
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Following is a description of the fields of the AMOD bytes from the above diagram.
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### T: Type
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The "T" field describes the data type of the following operand.
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|Value |Interpretation |
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|------|---------------|
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| 0 | Byte |
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| 1 | Word (2 bytes)|
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### MOD: Mode
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The four "MOD" bits describe the addressing mode of the following operand.
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|Value |Interpretation |
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|------|----------------------------------|
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| 0 | Immediate |
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| 1 | Register Direct |
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| 2 | Memory Direct |
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| 3 | Register Direct + Displacement |
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| 4 | Memory Direct + Displacement |
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| 5 | Register Indirect |
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| 6 | Memory Indirect |
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| 7 | Register Indirect + Displacement |
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| 8 | Memory Indirect + Displacement |
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### DSP: Displacement
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The three "DSP" bits specify a displacement to be added to the operand.
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|Value |Bytes Displacement |
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|------|-------------------|
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| 0 | 2 |
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| 1 | 4 |
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| 2 | 8 |
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| 3 | 16 |
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| 4 | 32 |
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| 5 | 64 |
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| 6 | 128 |
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| 7 | 256 |
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## Opcodes
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... | ... | |