main.asm
M

Tipo
Testo
Dimensioni
1 kB (1.503 byte)
Spazio di archiviazione
0 byteDi proprietà di un'altra persona
Posizione
part1.2
Proprietario
Matteo Castellani
Modificato
14:52 da Matteo Castellani
Creato
14:52
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;;**************************************************************
;* This stationery serves as the framework for a *
;* user application. For a more comprehensive program that *
;* demonstrates the more advanced functionality of this *
;* processor, please see the demonstration applications *
;* located in the examples subdirectory of the *
;* Freescale CodeWarrior for the HC12 Program directory *
;**************************************************************
; Include derivative-specific definitions
            INCLUDE 'derivative.inc'
; export symbols
            XDEF Entry, _Startup, main
; we use export 'Entry' as symbol. This allows us to
; reference 'Entry' either in the linker .prm file
; or from C/C++ later on
; code section

MyCode:     SECTION
main:
_Startup:
Entry:

start:      LDAA #$F0 ; load the DDRT register initialization value (bits 7 to 4 at ‘1’) in A
            STAA DDRT ; write the content of A to the DDRT register
            STAA PTT ; turn off the 4 LEDsDDRT (writing ‘1’)
            LDX #1000

loop_X:     CPX #0
            BEQ xor_A
            DEX
            BRA loop_X

loop_Y:     LDY #1000
            CPY #0
            BEQ done_Y
            DEY
            BRA loop_Y

done_Y:     JMP loop_X

xor_A:      EORA #$F0
            JMP ppt_A

ppt_A:      STAA PTT ; turn off the 4 LEDsDDRT (writing ‘1’)
            LDX #1000
            JMP loop_X