如何激活汇编程序中的引脚？

Question

I want to activate the 23 pin to light an LED

      ; Reset Vector
      rjmp   Start
      
Start:  
      ldi r16, 0x00     ;Cargar el registro de trabajo 16 al valor 0
      out DDRB, r16         ;Asignar al puerto B el valor del registro 16
      ldi r16, 0xFF     ;Carga el registro de trabajo 16, el valor FF
      out DDRC, r16     ;Asignar al puerto C el valor del registro 16
      
Loop:
      in r16, PINB      ;Lee puerto B
      out PORTC, r16        ;Escribe en puerto C lo leído
      ldi PORTC, 1
      rjmp Loop

Answer 1

If you want to enable PC0 (pin 23) output then you need to set bit #0 in both DDRC (which enables output driver at the pin) and PORTC (which selects high output level). You can either use OUT command to write 8bit value to an I/O register:

ldi r16, 0x01
out PORTC, r16
out DDRC, r16

or you can use sbi instruction to set a bit in one of first 32 I/O registers:

sbi PORTC, 0
sbi DDRC, 0

Answer 2

How LED on PC0 is connected? Provide schematics. Why D1 is connected to two ports? PC1 and PC5.