# r16

| number | instruction | argument 1 | argument 2 | fullname             | explanation                                       |
|-------:|:-----------:|------------|------------|----------------------|---------------------------------------------------|
|   0x00 |     HLT     |            |            | Halt                 | halts the CPU                                     |
|   0x01 |     ADD     | value 1    | value 2    | Add                  | ACU = value 1 + value 2                           |
|   0x02 |     SUB     | value 1    | value 2    | Subtract             | ACU = value 1 - value 2                           |
|   0x03 |     MUL     | value 1    | value 2    | Multiply             | ACU = value 1 * value 2                           |
|   0x04 |     DIV     | value 1    | value 2    | Divide               | ACU = value 1 / value 2                           |
|   0x05 |     LBS     | value      | amount     | Left Bit-Shift       | ACU = value << amount                             |
|   0x06 |     RBS     | value      | amount     | Right Bit-Shift      | ACU = value << amount                             |
|   0x07 |     BAN     | value 1    | value 2    | Bitwise And          | ACU = value 1 & value 2                           |
|   0x08 |     BOR     | value 1    | value 2    | Bitwise Or           | ACU = value 1 \                                   |
|   0x09 |     BXO     | value 1    | value 2    | Bitwise Exclusive Or | ACU = value 1 ^ value 2                           |
|   0x0A |     BNO     | value      |            | Bitwise Not          | ACU = ~ value                                     |
|   0x0B |     PUS     | value      |            | Push                 | pushes value onto the stack                       |
|   0x0C |     POP     |            |            | Pop                  | pops a value from the stack and stores it in ACU  |
|   0x0D |     JMP     | address    |            | Jump                 | jumps to address                                  |
|   0x0E |     JEQ     | address    | value      | Jump If Equal        | jumps to address, if value is equal to ACU        |
|   0x0F |     JNZ     | address    | value      | Jump If Not Zero     | jumps to address, if value is not zero            |
|   0x10 |     CAL     | address    |            | Call                 | pushes PC + 1 to the stack, then jumps to address |
|   0x11 |     RET     |            |            | Return               | pops value from stack and jumps to it             |
|   0x12 |     REG     | int type   | address    | Register Interrupt   | registers int type to address                     |
|   0x13 |     INT     | int type   |            | Interrupt            | interrupts as int type                            |
|   0x14 |     INP     |            |            | Input                | inputs a character into ACU                       |
|   0x15 |     OUT     | value      |            | Output               | outputs value                                     |
|   0x16 |     DIN     | location   |            | Disk In              | reads value from disk at location to ACU          |
|   0x17 |     DOT     | location   | value      | Disk Out             | writes value to disk at location                  |
|   0x18 |     MOV     | value 1    | value 2    | Move                 | move value 2 to value 1                           |

| Number | Register | Usage           |
|-------:|---------:|-----------------|
|    0x0 |       R0 | general usage   |
|    0x1 |       R1 | general usage   |
|    0x2 |       R2 | general usage   |
|    0x3 |       R3 | general usage   |
|    0x4 |      ACU | Accumulator     |
|    0x5 |       PC | Program Counter |
|    0x6 |       SP | Stack Pointer   |

|  Area of RAM  | reserved | Writable | usage             |
|:-------------:|:--------:|:--------:|-------------------|
| 00000 - 00064 |    YES   |    NO    | system header     |
| 00064 - 65023 |    NO    |    YES   | executable        |
| 65023 - 65279 |    YES   |    YES   | interupt pointers |
| 65279 - 65535 |    YES   |    YES   | stack             |

| BYTE 1 |        |            |            | BYTE 2     | BYTE 2     |
|--------|--------|------------|------------|------------|------------|
| OPCODE | UNUSED | ARG 1 INFO | ARG 2 INFO | ARGUMENT 1 | ARGUMENT 2 |
| 8 bits | 4 bits | 2 bits     | 2 bits     | 16 bits    | 16 bits    |

| State | Argument Interpretation                     |
|------:|---------------------------------------------|
|   0x0 | Value in argument                           |
|   0x1 | Value in register                           |
|   0x2 | Value in RAM                                |
|   0x3 | Value in RAM, at address stored in register |