/*
  Praktikum: Simulasi Register & Flag
  Dosen: Muhammad Ikhwan Fathulloh
  Tujuan:
    - Memahami fungsi register umum (R0–R31)
    - Melihat status bit flag (C, Z, N, V, S) secara visual dengan LED
*/

#define LED_C 2  // Carry
#define LED_Z 3  // Zero
#define LED_N 4  // Negative
#define LED_V 5  // Overflow
#define LED_S 6  // Sign

byte R0, R1, R2;  // Simulasi register umum
bool C, Z, N, V, S; // Flag status

void setup() {
  Serial.begin(9600);
  pinMode(LED_C, OUTPUT);
  pinMode(LED_Z, OUTPUT);
  pinMode(LED_N, OUTPUT);
  pinMode(LED_V, OUTPUT);
  pinMode(LED_S, OUTPUT);
  
  Serial.println("=== Simulasi Register dan Flag ===");
}

void loop() {
  R0 = random(0, 128);   // nilai acak 0–127
  R1 = random(0, 128);
  R2 = R0 + R1;          // operasi penjumlahan

  // Flag Logika
  C = (R2 > 255);           // Carry
  Z = (R2 == 0);            // Zero
  N = (R2 & 0x80);          // Negative (bit 7)
  V = ((R0 & 0x80) == (R1 & 0x80)) && ((R0 & 0x80) != (R2 & 0x80)); // Overflow
  S = N ^ V;                // Sign = N XOR V

  // Tampilkan di Serial Monitor
  Serial.println("----------------------");
  Serial.print("R0: "); Serial.println(R0);
  Serial.print("R1: "); Serial.println(R1);
  Serial.print("R2: "); Serial.println(R2);
  Serial.print("Flags -> C: "); Serial.print(C);
  Serial.print(" | Z: "); Serial.print(Z);
  Serial.print(" | N: "); Serial.print(N);
  Serial.print(" | V: "); Serial.print(V);
  Serial.print(" | S: "); Serial.println(S);

  // Visualisasi LED
  digitalWrite(LED_C, C);
  digitalWrite(LED_Z, Z);
  digitalWrite(LED_N, N);
  digitalWrite(LED_V, V);
  digitalWrite(LED_S, S);

  delay(1500);
}