/*
  Wokwi Custom XOR chip example

  No code runs on the ATtiny85 - all the logic is inside xor.chip.c
*/


void setup() {}

void loop() {}


xor-chip-example.ino

diagram.json

// Wokwi Custom Chip - For information and examples see:
// https://link.wokwi.com/custom-chips-alpha
//
// SPDX-License-Identifier: MIT
// Copyright (C) 2022 Uri Shaked / wokwi.com

#include "wokwi-api.h"
#include <stdio.h>
#include <stdlib.h>

DEFINE_PIN(VCC);
DEFINE_PIN(GND);
DEFINE_PIN(A);
DEFINE_PIN(B);
DEFINE_PIN(Q);

typedef struct {
  pin_t pin_a;
  pin_t pin_b;
  pin_t pin_q;
} chip_state_t;

static void update_output(chip_state_t *chip) {
  uint32_t a = pin_read(chip->pin_a);
  uint32_t b = pin_read(chip->pin_b);
  uint32_t q = a ^ b;
  printf("Update output: %d %d => %d\n", a, b, q);
  pin_write(chip->pin_q, a ^ b);
}

void* chip_init() {
  chip_state_t *chip = malloc(sizeof(chip_state_t));
  chip->pin_a = pin_init("A", INPUT);
  chip->pin_b = pin_init("B", INPUT);
  chip->pin_q = pin_init("Q", OUTPUT);
  pin_watch(chip->pin_a, BOTH);
  pin_watch(chip->pin_b, BOTH);
  update_output(chip);
  return chip;
}

bool EXPORT(chip_pin_change)(chip_state_t *chip, uint32_t pin, uint32_t value) {
  update_output(chip);
}