119 lines
1.8 KiB
NASM
119 lines
1.8 KiB
NASM
|
; lecture de la liaison série
|
||
|
|
||
|
.equ RAMEND = 0x21FF
|
||
|
.equ SPH = 0x3E
|
||
|
.equ SPL = 0x3D
|
||
|
|
||
|
.equ UBRR0H = 0x00C5
|
||
|
.equ UBRR0L = 0x00C4
|
||
|
.equ UCSR0A = 0x00C0
|
||
|
.equ UCSR0B = 0x00C1
|
||
|
.equ UCSR0C = 0x00C2
|
||
|
.equ UDR0 = 0x00C6
|
||
|
|
||
|
.org 0x0000
|
||
|
; Vecteur RESET
|
||
|
jmp debut
|
||
|
|
||
|
.org 0x0080
|
||
|
debut:
|
||
|
; initialisation du pointeur de pile
|
||
|
ldi r28,low(RAMEND)
|
||
|
ldi r29,high(RAMEND)
|
||
|
out SPL, r28
|
||
|
out SPH, r29
|
||
|
|
||
|
; UBRR0H <- 3
|
||
|
LDI R16,3
|
||
|
STS UBRR0H,R16
|
||
|
|
||
|
; UBRR0L <- 64
|
||
|
LDI R16,64
|
||
|
STS UBRR0L,R16
|
||
|
|
||
|
; UCSR0A <- 0b00000110
|
||
|
LDI R16,0b00000110
|
||
|
STS UCSR0A,R16
|
||
|
|
||
|
; UCSR0B <- 0b00011000
|
||
|
LDI R16,0b00011000
|
||
|
STS UCSR0B,R16
|
||
|
|
||
|
; UCSR0C <- 0b00000110
|
||
|
LDI R16,0b00000110
|
||
|
STS UCSR0C,R16
|
||
|
|
||
|
|
||
|
boucle:
|
||
|
; attend qu'un caractère arrive
|
||
|
; si (UCSR0a & 0x80) == 0 saut boucle
|
||
|
LDS R16,UCSR0a
|
||
|
ANDI R16,0x80
|
||
|
PUSH R16
|
||
|
LDI R16,0
|
||
|
POP R17
|
||
|
CP R17,R16
|
||
|
BREQ eti0
|
||
|
CLR R16
|
||
|
RJMP eti1
|
||
|
eti0:
|
||
|
LDI R16,0x01
|
||
|
eti1:
|
||
|
TST R16
|
||
|
BREQ eti2
|
||
|
JMP boucle
|
||
|
eti2:
|
||
|
|
||
|
|
||
|
; R20 <- UDR0
|
||
|
LDS R16,UDR0
|
||
|
MOV R20,R16
|
||
|
|
||
|
|
||
|
; si R20 == 'a' alors R20 <- 'A'
|
||
|
MOV R16,R20
|
||
|
PUSH R16
|
||
|
LDI R16,'a'
|
||
|
POP R17
|
||
|
CP R17,R16
|
||
|
BREQ eti3
|
||
|
CLR R16
|
||
|
RJMP eti4
|
||
|
eti3:
|
||
|
LDI R16,0x01
|
||
|
eti4:
|
||
|
TST R16
|
||
|
BREQ eti5
|
||
|
LDI R16,'A'
|
||
|
MOV R20,R16
|
||
|
eti5:
|
||
|
|
||
|
; si R20 == 'e' alors R20 <- 'E'
|
||
|
MOV R16,R20
|
||
|
PUSH R16
|
||
|
LDI R16,'e'
|
||
|
POP R17
|
||
|
CP R17,R16
|
||
|
BREQ eti6
|
||
|
CLR R16
|
||
|
RJMP eti7
|
||
|
eti6:
|
||
|
LDI R16,0x01
|
||
|
eti7:
|
||
|
TST R16
|
||
|
BREQ eti8
|
||
|
LDI R16,'E'
|
||
|
MOV R20,R16
|
||
|
eti8:
|
||
|
|
||
|
|
||
|
; UDR0 <- R20
|
||
|
STS UDR0,R20
|
||
|
|
||
|
|
||
|
; saut boucle
|
||
|
JMP boucle
|
||
|
|
||
|
|
||
|
|