arduinoでアセンブラ

arduino unoでインライン アセンブラをやってみました。

サンプルコード

byte b[32];
byte g;
void print_r()
{
    asm volatile(
        "push   r16 \n\t"
        "push   r17 \n\t"
        "push   r18 \n\t"
        "push   r19 \n\t"
        "push   r20 \n\t"
        "push   r21 \n\t"
        "push   r22 \n\t"
        "push   r23 \n\t"
        "push   r24 \n\t"
        "push   r25 \n\t"
        "push   r26 \n\t"
        "push   r27 \n\t"
        "push   r28 \n\t"
        "push   r29 \n\t"
        "push   r30 \n\t"
        "push   r31 \n\t"
        "sts    (b),        r0 \n\t"
        "sts    (b + 1),    r1 \n\t"
        "sts    (b + 2),    r2 \n\t"
        "sts    (b + 3),    r3 \n\t"
        "sts    (b + 4),    r4 \n\t"
        "sts    (b + 5),    r5 \n\t"
        "sts    (b + 6),    r6 \n\t"
        "sts    (b + 7),    r7 \n\t"
        "sts    (b + 8),    r8 \n\t"
        "sts    (b + 9),    r9 \n\t"
        "sts    (b + 10),   r10 \n\t"
        "sts    (b + 11),   r11 \n\t"
        "sts    (b + 12),   r12 \n\t"
        "sts    (b + 13),   r13 \n\t"
        "sts    (b + 14),   r14 \n\t"
        "sts    (b + 15),   r15 \n\t"
        "sts    (b + 16),   r16 \n\t"
        "sts    (b + 17),   r17 \n\t"
        "sts    (b + 18),   r18 \n\t"
        "sts    (b + 19),   r19 \n\t"
        "sts    (b + 20),   r20 \n\t"
        "sts    (b + 21),   r21 \n\t"
        "sts    (b + 22),   r22 \n\t"
        "sts    (b + 23),   r23 \n\t"
        "sts    (b + 24),   r24 \n\t"
        "sts    (b + 25),   r25 \n\t"
        "sts    (b + 26),   r26 \n\t"
        "sts    (b + 27),   r27 \n\t"
        "sts    (b + 28),   r28 \n\t"
        "sts    (b + 29),   r29 \n\t"
        "sts    (b + 30),   r30 \n\t"
        "sts    (b + 31),   r31 \n\t"
        "in     r16,    0x3f \n\t"
        "sts    (g),    r16 \n\t"
        ::: "r16"
    );
    for (int i = 0; i < 32; i++)
    {
        Serial.print("r");
        if (i < 10)
        {
            Serial.print(0);
        }
        Serial.print(i);
        Serial.print(" = ");
        Serial.print(b[i] >> 4, HEX);
        Serial.print(b[i] & 0x0f, HEX);
        if ((i + 1) % 8)
        {
            Serial.print(" ");
        }
        else
        {
            Serial.println(";");
        }
    }
    Serial.print("flag: c = ");
    Serial.print(g & 0x01);
    Serial.print(" z = ");
    Serial.print((g >> 1) & 0x01);
    Serial.print(" n = ");
    Serial.print((g >> 2) & 0x01);
    Serial.print(" v = ");
    Serial.print((g >> 3) & 0x01);
    Serial.print(" s = ");
    Serial.print((g >> 4) & 0x01);
    Serial.print(" h = ");
    Serial.print((g >> 6) & 0x01);
    Serial.print(" t = ");
    Serial.print((g >> 6) & 0x01);
    Serial.print(" i = ");
    Serial.println(g >> 7);
    Serial.println(";");
    asm volatile(
        "lds    r31,    (g) \n\t"
        "out    0x3f,   r31 \n\t"
        "pop    r31 \n\t"
        "pop    r30 \n\t"
        "pop    r29 \n\t"
        "pop    r28 \n\t"
        "pop    r27 \n\t"
        "pop    r26 \n\t"
        "pop    r25 \n\t"
        "pop    r24 \n\t"
        "pop    r23 \n\t"
        "pop    r22 \n\t"
        "pop    r21 \n\t"
        "pop    r20 \n\t"
        "pop    r19 \n\t"
        "pop    r18 \n\t"
        "pop    r17 \n\t"
        "pop    r16 \n\t"
        :::
    );
}
void setup()
{
    Serial.begin(9600);
}
void loop()
{
    print_r();
    delay(900);
}