m820241130004.asm

; (C) David Vajda
; 2024-11-30
; rs-232 - ccitt (5?) V.23/V.24 - recieve

.include "m8def.inc"

ldi r16, HIGH (RAMEND)
out SPH, r16
ldi r16, LOW (RAMEND)
out SPL, r16

ldi r16, HIGH (25)
out UBRRH, r16
ldi r16, LOW (25)
out UBRRL, r16

ldi r16, (1 << URSEL) | (1 << UCSZ1) | (1 << UCSZ0)
out UCSRC, r16

ldi r16, (1 << TXEN)
out UCSRB, r16

loop1:
ldi r16, 'w'
rcall v24transmit
ldi r16, 'w'
rcall v24transmit
ldi r16, 'w'
rcall v24transmit
ldi r16, '.'
rcall v24transmit
ldi r16, 'y'
rcall v24transmit
ldi r16, 'u'
rcall v24transmit
ldi r16, 'n'
rcall v24transmit
ldi r16, '7'
rcall v24transmit
ldi r16, 'x'
rcall v24transmit
ldi r16, '.'
rcall v24transmit
ldi r16, 'd'
rcall v24transmit
ldi r16, 'e'
rjmp loop1

v24transmit:
sbis UCSRA, UDRE
rjmp v24transmit
out UDR, r16
ret