Stack Machine

Stack Machine emulates physical machine, operands in memory structure are stored in stack data structure.

|   +   | <- operator
|-------|
|   4   | <- 2. top of stack (push 4)
|-------|
|   3   | <- 1. top of stack (push 3)
|-------|

|   4   | <- 3. top of stack (pop)
|-------|
|   3   |
|-------|
|       |
|-------|

|   3   | <- 4. top of stack (pop)
|-------|
|       |
|-------|
|       |
|-------|

|       |
|-------|
|       |
|-------|
|   7   | <- 5. top stack (push = 3 + 4)
|-------|

HALT

Ones program finishes, machine goes into HALT STATE.

During lifetime of machine, it passes though various states and stages:

STATES

• STATE_RESET: Initial state of machine
• STATE_RUN: Running state of machine [executing program]
• STATE_HALT: Stopped state of machine [program finished]

STAGES

• FETCH: It fetches the instruction from memory
• DECODE: Decodes the type of instruction [operator or operand]
• EXECUTE: Performs action based on decoded output.

Inspiration: @Philip Bohun