rc_servos: most critical variables as registers

diff --git a/main.c b/main.c
index e733e81..a27bf10 100644 (file)
--- a/main.c
+++ b/main.c
@@ -19,10 +19,11 @@ static struct servo servo_table[] = {
                .command = 1023,
        },
 };
+
 static volatile uint8_t rxbuf[16];
-static volatile uint8_t rxlen;
-static volatile uint8_t portval;
-static volatile uint8_t done;
+register uint8_t rxlen asm("r2");
+register uint8_t done asm("r3");
+register uint8_t portval asm("r4");
 
 SIGNAL(TIMER1_COMPA_vect)
 {