mirror of
https://github.com/sergeyyarkov/attiny24a_led-blink-example.git
synced 2026-10-11 10:18:57 +03:00
71 lines
2.1 KiB
NASM
71 lines
2.1 KiB
NASM
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; Project name: led-blink-example
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; Description: Blink an led every one second
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; Source code: https://github.com/sergeyyarkov/attiny24a_led-blink-example
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; Device: ATtiny24A
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; Package: 14-pin-PDIP_SOIC
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; Assembler: gavrasm v5.0
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;
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; Written by Sergey Yarkov 23.09.2021
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.device ATtiny24A ; Setup device name
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.list ; Enable listing
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.macro init_stack_p ; Setup stack pointer
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ldi @0, low(@1)
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out SPL, @0
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.endm
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.equ LED_DIR = DDRA ; LED Direction
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.equ LED_PORT = PORTA ; LED Port
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.equ LED_PIN = PINA0 ; LED Pin
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.equ oVal = 20 ; If set to 0, then this value is decremented to 255
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.equ iVal = 10000 ; Value of cycles in inner delay loop
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.org 0x00 ; Start program at 0x00
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.cseg ; Code segment
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main: ; Start up program
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init_stack_p r16, RAMEND
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rcall init_ports ; Initialize MCU ports
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rcall _r_inner_delay_loop ; Initialize delay inner loop value
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rcall _r_outer_delay_loop ; Intialize delay outer loop value
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loop: ; Program loop
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rcall toggle_led ; Toggle an LED
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rcall delay_1s ; Delay for 1 sec
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rjmp loop ; Jump to program loop again
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toggle_led: ; Toggle an LED
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eor r17, r16 ; Toggle bit
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out LED_PORT, r17 ; Update port of LED
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ret
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init_ports: ; Init MCU ports
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ldi r16, (1<<LED_PIN) ; Load to r16 high bit
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out LED_DIR, r16 ; Set LED direction to output
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ret
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delay_1s_outer_l:
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rcall _r_inner_delay_loop
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delay_1s:
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sbiw r24, 1 ; Decrement inner loop value
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brne delay_1s ; Jump to inner loop again
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rcall _r_inner_delay_loop ; Reset inner loop value
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dec r18 ; Decremnt outer loop value
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brne delay_1s_outer_l ; Jump to outer loop again
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rcall _r_outer_delay_loop
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ret
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_r_inner_delay_loop: ; Reset inner delay loop
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ldi r24, low(iVal)
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ldi r25, high(iVal)
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ret
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_r_outer_delay_loop: ; Reset outer delay loop
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ldi r18, oVal
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ret |