122 lines
6.0 KiB
Org Mode
122 lines
6.0 KiB
Org Mode
#+OPTIONS: toc:nil num:nil <:nil \n:nil ::nil timestamp:nil *:nil ':nil
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#+HTML_HEAD: <link rel="stylesheet" type="text/css" href="style.css"/>
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#+EXPORT_FILE_NAME: index.html
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#+title: ocpu
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* GRU ocpu - yet another cpu design
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** Features
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- little endian
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- 8-bit (maybe will be changed in future)
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** Registers
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|----------+----------+-----------------|
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| Register | Category | Description |
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|----------+----------+-----------------|
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| A | General | 0x0A |
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|----------+----------+-----------------|
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| B | General | 0x0B |
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|----------+----------+-----------------|
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| C | General | 0x0C |
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|----------+----------+-----------------|
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| D | | 0x0D |
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|----------+----------+-----------------|
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| E | | 0x0E |
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|----------+----------+-----------------|
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| F | | 0x0F |
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|----------+----------+-----------------|
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| PC | Pointer | Program Counter |
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|----------+----------+-----------------|
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| SP | Poiner | Stack Pointer |
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|----------+----------+-----------------|
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| ZF | Flag | Zero Flag |
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|----------+----------+-----------------|
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| NF | Flag | Negative Flag |
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|----------+----------+-----------------|
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| CF | Flag | Carry Flag |
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| | | |
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|----------+----------+-----------------|
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| OF | Flag | Overflow Flag |
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** Instuctions
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|--------------+--------+-------------------------------------------|
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| Instructions | Opcode | Description |
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|--------------+--------+-------------------------------------------|
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| MOV | 0x01 | Place value to register. |
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| | | Takes 2 bytes as arguments: |
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| | | 1 - Opcode of register |
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| | | 2 - Value |
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| | | |
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|--------------+--------+-------------------------------------------|
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| ADD | 0x10 | |
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|--------------+--------+-------------------------------------------|
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| ADC | 0x11 | |
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|--------------+--------+-------------------------------------------|
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| SUB | 0x12 | |
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|--------------+--------+-------------------------------------------|
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| MUL | 0x13 | |
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|--------------+--------+-------------------------------------------|
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| DIV | 0x14 | |
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|--------------+--------+-------------------------------------------|
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| INC | 0x15 | Increment |
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|--------------+--------+-------------------------------------------|
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| DEC | 0x16 | Decrement |
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|--------------+--------+-------------------------------------------|
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| AND | 0x20 | |
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|--------------+--------+-------------------------------------------|
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| OR | 0x21 | |
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|--------------+--------+-------------------------------------------|
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| NOR | 0x22 | |
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|--------------+--------+-------------------------------------------|
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| XOR | 0x23 | |
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|--------------+--------+-------------------------------------------|
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| NAND | 0x24 | |
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|--------------+--------+-------------------------------------------|
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| CMP | 0x25 | |
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|--------------+--------+-------------------------------------------|
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| PUSH | 0x30 | |
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|--------------+--------+-------------------------------------------|
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| POP | 0x31 | |
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|--------------+--------+-------------------------------------------|
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| JMP | 0x40 | |
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|--------------+--------+-------------------------------------------|
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| JSR | 0x41 | Jump to subroutine |
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|--------------+--------+-------------------------------------------|
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| JC | 0x42 | Jump with carry |
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|--------------+--------+-------------------------------------------|
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| JNC | 0x43 | Jump without carry |
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|--------------+--------+-------------------------------------------|
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| JZ | 0x44 | Jump if zero |
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|--------------+--------+-------------------------------------------|
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| JNZ | 0x45 | Jump if non-zero |
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|--------------+--------+-------------------------------------------|
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| RTS | 0x42 | Return from subroutine |
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|--------------+--------+-------------------------------------------|
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| INB | 0x50 | Copies value from I/O port to destination |
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|--------------+--------+-------------------------------------------|
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| OUTB | 0x51 | Copies value from operand to I/O port |
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|--------------+--------+-------------------------------------------|
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| NOP | 0x90 | No operation |
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0x0* - MOV instructions (maybe it will for LDA or something)
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0x1* - Arithmetic (ADD, SUB and others)
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0x2* - Logic (AND, OR and others)
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0x3* - Stack Operations (PUSH, POP)
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0x4* - Jumps
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0x5* - Ports Operations
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0x90 - NOP
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TODO: add interrupts
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TODO: add HLT
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TODO: make instructions for memory use
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