Make README more readable
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README.md
64
README.md
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@ -62,37 +62,39 @@ ignored. They don't have to be set to 0.
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### Opcodes
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| Opcode | Name | Function | Notes |
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|--------|---------------------------------------------|--------------------------------|----------------------------------|
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| `0` | `LDC c` (load constant) | `c -> ACC` | Bits 23-20 of `ACC` are set to 0 |
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| `1` | `LDV a` (load value) | `<a> -> ACC` | |
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| `2` | `STV a` (store value) | `ACC -> <a>` | |
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| `3` | `ADD a` | `ACC + <a> -> ACC` | |
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| `4` | `AND a` | `ACC and <a> -> ACC` | Bitwise operation |
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| `5` | `OR a` | `ACC or <a> -> ACC` | Bitwise operation |
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| `6` | `XOR a` | `ACC xor <a> -> ACC` | Bitwise operation |
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| `7` | `EQL a` (equal) | `(ACC == <a> ? -1 : 0) -> ACC` | |
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| `8` | `JMP a` (jump) | `a -> IAR` | |
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| `9` | `JMN a` (jump if negative) | `if (ACC < 0) {a -> IAR}` | |
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| `A` | `LDIV a` (load indirect value) | `<<a>> -> ACC` | |
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| `B` | `STIV a` (store indirect value) | `ACC -> <<a>>` | |
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| `C` | `CALL a` | `IAR -> RA; JMP a` | |
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| `D` | `LDVR d` (load value with relative offset) | `<SP + d> -> ACC` | |
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| `E` | `STVR d` (store value with relative offset) | `ACC -> <SP + d>` | |
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| `F0` | `HALT` | Halt execution | |
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| `F1` | `NOT` | `not ACC -> ACC` | Bitwise operation |
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| `F2` | `RAR` (rotate ACC right) | `ACC >> 1 -> ACC` | See below |
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| `F3` | `RET` (return) | `RA -> IAR` | |
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| `F4` | `LDSP` (load from SP) | `SP -> ACC` | |
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| `F5` | `STSP` (store to SP) | `ACC -> SP` | |
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| `F6` | `LDFP` (load from FP) | `FP -> ACC` | |
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| `F7` | `STFP` (store to FP) | `ACC -> FP` | |
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| `F8` | `LDRA` (load from RA) | `RA -> ACC` | |
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| `F9` | `STRA` (store to RA) | `ACC -> RA` | |
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| `FA` | `ADC c` (add constant) | `ACC + c -> ACC` | See below |
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| Opcode | Name | Function |
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|--------|---------------------------------------------|--------------------------------|
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| `0` | `LDC c` (load constant) | `c -> ACC` |
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| `1` | `LDV a` (load value) | `<a> -> ACC` |
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| `2` | `STV a` (store value) | `ACC -> <a>` |
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| `3` | `ADD a` | `ACC + <a> -> ACC` |
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| `4` | `AND a` | `ACC and <a> -> ACC` |
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| `5` | `OR a` | `ACC or <a> -> ACC` |
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| `6` | `XOR a` | `ACC xor <a> -> ACC` |
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| `7` | `EQL a` (equal) | `(ACC == <a> ? -1 : 0) -> ACC` |
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| `8` | `JMP a` (jump) | `a -> IAR` |
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| `9` | `JMN a` (jump if negative) | `if (ACC < 0) {a -> IAR}` |
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| `A` | `LDIV a` (load indirect value) | `<<a>> -> ACC` |
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| `B` | `STIV a` (store indirect value) | `ACC -> <<a>>` |
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| `C` | `CALL a` | `IAR -> RA; JMP a` |
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| `D` | `LDVR d` (load value with relative offset) | `<SP + d> -> ACC` |
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| `E` | `STVR d` (store value with relative offset) | `ACC -> <SP + d>` |
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| `F0` | `HALT` | Halt execution |
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| `F1` | `NOT` | `not ACC -> ACC` |
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| `F2` | `RAR` (rotate ACC right) | `ACC >> 1 -> ACC` |
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| `F3` | `RET` (return) | `RA -> IAR` |
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| `F4` | `LDRA` (load from RA) | `RA -> ACC` |
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| `F5` | `STRA` (store to RA) | `ACC -> RA` |
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| `F6` | `LDSP` (load from SP) | `SP -> ACC` |
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| `F7` | `STSP` (store to SP) | `ACC -> SP` |
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| `F8` | `LDFP` (load from FP) | `FP -> ACC` |
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| `F9` | `STFP` (store to FP) | `ACC -> FP` |
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| `FA` | `ADC c` (add constant) | `ACC + c -> ACC` |
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- `RAR` shifts all bits in the `ACC` right by one. The rightmost bit wraps around to the leftmost position.
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- `ADC c` interprets bits 15-0 as a signed integer, whose value is then added to the `ACC`'s current value.
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* `LDC c` sets bits 23-20 of `ACC` to 0.
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* `ADD a`, `AND a`, `OR a`, `XOR a` and `NOT` are bitwise operations
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* `RAR` shifts all bits in the `ACC` right by one. The rightmost bit wraps around to the leftmost position.
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* `ADC c` interprets bits 15-0 as a signed integer, whose value is then added to the `ACC`'s current value.
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## File format
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@ -118,7 +120,7 @@ The registers and memory are stored as follows:
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| Word | Content |
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|--------------:|-------------|
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| 0 | `IR` |
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| 0 | `IAR` |
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| 1 | `ACC` |
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| 2 | `RA` |
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| 3 | `SP` |
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