ytd_12-bit_computer/docs/ytd 12-bit computer.md

YTD 12-bit Computer

Yeahbut, aka Kyler Olsen

NOTICE: Most of this document is unfinished.

It is a custom computer and instruction set architecture. It also has its own assembly language with assembler written in Python. Custom high level language coming soon!

ISA

Assembly Language

Registers

• ZR
• PC
• SP
• MP
• D0
• D1
• D2
• D3

Zero Operand Instructions

• NOP
• HLT
• BNZ
• BNA
• BNP
• BNN

One Operand Instructions

• GLA Destination Register
• GET Destination Register
• LOD Destination Register
• STR Source Register
• POP Destination Register
• PSH Source Register
• LIU Immediate Value
• LDI Immediate Value
• LDI :Label
• LIL Immediate Value

Two Operand Instructions

• LSH Destination Register Source Register
• RSH Destination Register Source Register
• INC Destination Register Source Register
• DEC Destination Register Source Register

Three Operand Instructions

• AND Destination Register Source Register A Source Register B
• OR Destination Register Source Register A Source Register B
• SUB Destination Register Source Register A Source Register B
• XOR Destination Register Source Register A Source Register B
• NOR Destination Register Source Register A Source Register B
• NAD Destination Register Source Register A Source Register B
• ADD Destination Register Source Register A Source Register B

High Level Language

WIP

About

• Paradigm: Multi-Paradigm: Procedural (Imperative), Structured
• Designer: Kyler Olsen
• Created: Future
• Typing Discipline: Typeless Static, Weak
• Platform: ytd 12-bit computer, ytd 12-bit emulator (from pytd12dk, multi-platform)
• License: Tentatively MIT
• Filename extension: .ytd12c
• Compiler Implementations: pytd12dk (Python), ytd12nc (bootstrapped compiler)

Lexical

Directives

Directives start with # and end at the end of a line. They are used to give additional instructions to the compiler.

Comments

Comments can either be single-line comments or multi-line comments.

Single-line comments start with // and end at the end of a line.

Multi-line comments start with /* and end with */.

pytd12dk implementation detail: Comments and their content are ultimately ignored by the lexer after they are tokenized. There are no comments in the output of the lexer.

Identifiers

Can be up to 15 characters in length, and are case sensitive. They cannot be a keyword.

Identifier ::= ID_Start ID_Continue*
ID_Start ::= <Any latin alphabet ligature or an underscore: "A"-"Z", "a"-"z", "_">
ID_Continue ::= ID_Start | <Any decimal ligature: "0"-"9">

Keywords

struct      fn          enum        static
if          else        do          while
for         pub         let         break
continue    True        False       None
unsigned    int         fixed       float

Literals

Number Literals

number ::=  decinteger | bininteger | octinteger | hexinteger | pointfloat | exponentfloat
decinteger ::=  nonzerodigit (["_"] digit)* | "0"+ (["_"] "0")*
bininteger ::=  "0" ("b" | "B") (["_"] bindigit)+
octinteger ::=  "0" ("o" | "O") (["_"] octdigit)+
hexinteger ::=  "0" ("x" | "X") (["_"] hexdigit)+
nonzerodigit ::=  "1"..."9"
digit ::=  "0"..."9"
bindigit ::=  "0" | "1"
octdigit ::=  "0"..."7"
hexdigit ::=  digit | "a"..."f" | "A"..."F"
pointfloat    ::=  ([digitpart] fraction) | (digitpart ".")
exponentfloat ::=  (digitpart | pointfloat) exponent
digitpart     ::=  digit (["_"] digit)*
fraction      ::=  "." digitpart
exponent      ::=  ("e" | "E") ["+" | "-"] digitpart

Character Literals

Character Literals must be on one line and begin and end with '. They can only have one printable ascii character or escape code.

String Literals

String Literals must be on one line and begin and end with ". They can have a unspecified number of printable ascii characters and escape codes.

Escape Codes

Code	Meaning
\n	Line Feed
\r	Return Carriage
\0	Null Character
\'	Single Quotation Mark (In char literals)
\"	Double Quotation Mark (In str literals)

Punctuation

++      --      @       $       +       -
*       /       %       ~       &       |
^       <<      >>      =       +=      -=
*=      /=      %=      &=      |=      ^=
<<=     >>=     !       &&      ||      ==
!=      <       <=      >       >=      ?
{       }       [       ]       (       )
.       ->      ,       ;       :

Syntax

ProgramFile

A ProgramFile contains a number of Directives and BlockHeaders.

Directives

BlockHeaders

A BlockHeaders contains a Header and a number of Statements, Directives, and BlockHeaders.

Semantics

Scratch Area

Operator Operand Counts

• Unitary: ++, --, @, $
• Binary: [ ], +, -, *, /, %, ~, &, |, ^, <<, >>, =, +=, -=, *=, /=, %=, &=, |=, ^=, <<=, >>=, !, &&, ||, ==, !=, <, <=, >, >=
• Ternary: ? :

Operator Precedence

• Assignment: =, +=, -=, *=, /=, %=, &=, |=, ^=, <<=, >>=
• Ternary Operator: ? :
• Equality and order testing: ==, !=, <, <=, >, >=
• Boolean logic: !, &&, ||
• Arithmetic: +, -, *, /, %
• Bitwise: ~, &, |, ^, <<, >>
• Increment and decrement: ++, --
• Reference and dereference: @, $, [ ]

Keywords

• Types: unsigned, int, fixed, float
• Structural: if, else, do, while, for, break, continue
• Constants: True, False, None
• Other: struct, fn, enum, static, pub, let

Delimiters

.       ->      ,       (       )
{       }       [       ]       ;
:

Escape Codes

Code	Meaning
\0	Null Character
\a	Alert (Beep, Bell)
\b	Backspace
\e	Escape Character
\f	Formfeed Page Break*
\n	Line Feed
\r	Return Carriage
\t	Horizontal Tab
\v	Vertical Tab*
\\	Backslash
\'	Single Quotation Mark (In char literals)
\"	Double Quotation Mark (In str literals)

pytd12dk

pytd12dk (Python ytd 12-bit development kit) is a tool set written in Python to assist in developing software for the ytd 12-bit computer. It includes a compiler, assembler with linker, and emulator.

Compiler

Assembler

Emulator

ytd12nc

ytd12nc (ytd 12-bit native compiler) is a compiler and assembler with linker set written in the native high-level programming language and assembly language to compile software for the ytd 12-bit computer natively.

Currently development of ytd12nc has not yet started.

Bootstrapping

In order to compile the the compiler, we need a compiler to compile it. This process is called bootstrapping as it is like pulling ourselves up by our bootstraps. This requires writing a compiler in assembly language or another high-level programming language. In our case we are lucky to have the compiler that is apart of pytd12dk.

Compiler	Compiler Compiler	Compiler Compiler Compiler
pytd12dk	CPython	gcc, clang, or other C compiler
ytd12nc (a)	pytd12dk	CPython
ytd12nc (b)	ytd12nc (a)	pytd12dk
ytd12nc (c)	ytd12nc (b)	ytd12nc (a)
ytd12nc (d)	ytd12nc (c)	ytd12nc (b)