16TTAC-sim

A compiler and simulator written in TypeScript for an imaginary 16bit
Transport Triggered Architecture CPU.

The CPU

- Uses the TTA architecture
- Up to 128 sources and destinations each
- Accumulator and Address registers
- 16-bit fixed width instruction, with optional 16-bit operand
- 64 kiloword, or 128KB RAM size
- 256-word stack
- Conditional execution using Carry and Zero flags
- Halting support
- Built-in IO support

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- bits 15-9 - source
- bits 8-2 - destination
- bit 1 - if set, instruction is only executed if the carry flag is set
- bit 0 - if set, instruction is only executed if the zero flag is set

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All sources and destinations are completely customizable, but you can look here to see the descriptions of all of them that are available by default.

The assembly language

Here is a small code snippet that should explain the whole syntax:

``
//Comments are single line

//Some example variable declarations:
word var = 123
word var2 = 0x5
word string[10] = "hello"
word string2[10] = [09,98,'c']
word MUL_ARR[10][2] = [[0,1], [2,3], "a"]

//Some example instructions:
SOURCE => DESTINATION
SOURCE => DESTINATION c //Executes only if the carry flag is set
SOURCE => DESTINATION z //Executes only if the zero flag is set
SOURCE => DESTINATION c z //Executes only if the carry and the zero flag are set

//Source can also be a constant value, provided by the operand
123 => DESTINATION
0xFFFF => DESTINATION
'a' => DESTINATION

//Source can also be a reference to a variable
string => ADR
var2 => ADR

//Labels:
label:
123 => ACC
another_label:
string => PUSH
`

The Toolchain

The toolchain is written in TypeScript, it is made to work both in web and node.
It also works as a standalone tool that you can use with npx.

Using 16TTAC-sim as an npx tool

`
$ npx 16ttac-sim -h
$ npx 16ttac-sim examples/numbers.txt
`

Using 16TTAC-sim as a library

`
$ npm i 16ttac-sim

//Include the required files...

const parser = new Parser();
const compiler = new Compiler();
const program = new Command();

let simRunning = true;
const sim = new Sim({
haltCallback: () => {
console.log("\n\nHalting");
simRunning = false;
}
});

sim.initializeMemory(compiler.compile(parser.parse(sourceCode)));

while(simRunning) sim.singleStep();
`

For more complicated examples with IO, look at cli.ts and sim.test.ts.

Adding your own instructions

The main advantage of Transport Triggered Architecture is the ease of adding custom instructions, to do so you can extend the defaultInstructionDictionary
or you can create your own dictionary.

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A dictionary needs one source with isOperand` set for the toolchain to work correctly.