Setup timer0 and timer1

2025-12-25 22:43:49 +01:00
parent 39b6beb6f0
commit f5a6e1f055
1 changed files with 26 additions and 0 deletions
@@ -0,0 +1,26 @@
+#define __SFR_OFFSET 0
+#include <avr/io.h>
+
+; Timer0 will be static and used for the led
+timer0_set:
+    ldi     r16,        (1 << WGM01)                    ; Load 00000010 to register (bit 1=CTC)
+    out     TCCR0A,     r16                             ; On T/C Control Register A, enable CTC and COM0A0
+
+    ldi     r16,        244                             ; Load counter target limit value (ticks)
+    out     OCR0A,      r16                             ; Compare target to current counter
+
+; Timer1 will be dynamically changed in main
+timer1_ld:
+    ; Load 10011011 to register:
+    ;   CTC1   (Bit 7): Reset timer to 0 when it matches OCR1C
+    ;   COM1A0 (Bit 4): Toggle OC1A (PB1) when it matches OCR1A
+    ;   CS13, CS11, CS10 (Bits 3,1,0): Prescaler 1024 (1011)
+    ldi     r16,        (1 << CTC1) | (1 << COM1A0) | (1 << CS13) | (1 << CS11) | (1 << CS10)
+    out     TCCR1,      r16                             ; On T/C Control Register 1, enable: CTC1 COM1A0 CS13 CS11 CS10
+
+timer1_set:
+    ldi     r16,        256                             ; Load counter total  value (ticks)
+    ldi     r16,        5                               ; Load counter on value (ticks)
+    ; //TODO: change r16 on main and then call timer1_dyn to use the value already on r16 (so its dynamic)
+    out     OCR1C,      r16                             ; Compare target to current counter (frequency)
+    out     OCR1A,      r16                             ; Compare target to current counter (phase shift)