1.硬件电路
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2.测试程序（nasm汇编）
;------------------------------------------------------------------------------------------- ;长按学习板上的K4，会在串口上打印出 key0 event happen! ;------------------------------------------------------------------------------------------- ;2017.9.15 ;用nasm重新写原来的代码 ;推出配套的《在做中学微机原理》课程，与所销售的硬件相配套 ;从第一行程序开教，一步一步带你走入神秘的8086世界。 ; ;例程001 ;ex1.asm =example_1 ;8088启动,点亮系统板上的LED ;重点在于正确使用程序编辑环境，nasm汇编方法，EEprom的烧写方法 ; ;ex001----用下载到RAM中的程序，点亮系统板上的LED ;8088.asm是汇编源程序 ;8088.bin是编译生成的可下载执行的最终代码 ; ;编译很简单，双击make即可自动完成 ; ;Notepad++是我计算机上Notepad++的快捷方式 ;--------------------------------------------------------------------------------------------- led_port equ 800h _8255_port3 equ 203h _8255_porta equ 200h _8255_portb equ 201h _8255_portc equ 202h ;--------------------------------------------------------------------------------------------- org 2000h ;程序将由监控bios下载到内存RAM的地址（0000:2000） start: ;------------------------------------------------------ ;init part ;------------------------------------------------------ mov ax,0 mov ds,ax mov ss,ax mov sp,1fffh ;--------------------------------------------------------- ;8255 init ;--------------------------------------------------------- call _8255_init ;mov al,[LED_CODE] ;mov dx,_8255_porta ;out dx,al ;mov al,0feh ;mov dx,_8255_portb ;out dx,al st001: nop call _8255_disp call _8255_key ;----------------------------------------------------- ;点亮系统板上的LED ;----------------------------------------------------- ;MOV DX,800H ;800H是板子上8个LED的端口地址号 mov dx,led_port MOV AL,0aaH ;一亮一灭间隔点亮 OUT DX,AL call DELAY ;MOV DX,800H ;800H是板子上8个LED的端口地址号 mov dx,led_port MOV AL,00H ;一亮一灭间隔点亮 OUT DX,AL call DELAY mov ah,'$' call SEND ; lea di,STR1 ;nasm编译器不认 mov di, STR1 CALL STR_OUT mov di, STR3 CALL STR_OUT ;mov al,01010101b ;mov al,0f0h; ;out 25H,al ;hlt jmp st001 jmp start ;------------------------------------------------------------ ; DELAY PROC NEAR ;------------------------------------------------------------ ;push DELAY: PUSH CX PUSH BX NOP NOP mov bx,10 del1: mov cx,5882 del2: loop del2 dec bx jnz del1 ;pop cx ;pop bx POP BX POP CX RET ;------------------------------------------- ;pc16550 uart send by AH ;------------------------------------------- LSTAT EQU 1F5H DAT_165 EQU 1F0H SEND: ; PROC NEAR MOV DX,LSTAT WAITx: IN AL,DX TEST AL,20H JZ WAITx MOV AL,AH MOV DX,DAT_165 OUT DX,AL RET ;SEND ENDP ;------------------------------------------- ;串口打印字符串 ;------------------------------------------- STR_OUT :; PROC NEAR nop; LEA DI,STR1 STR_LOOP: ;MOV AH,BYTE PTR [DI] mov ah,byte [di] CMP AH,'$' JZ STR_EXIT CALL SEND INC DI JMP STR_LOOP STR_EXIT: NOP RET ;----------------------------- ;8255 init ;----------------------------- _8255_init: ;mov dx,203h mov dx, _8255_port3 ;mov al,80h mov al,89h;port a,b as output port c as input out dx,al ret _8255_disp: ;bit 0 mov al,[LED_CODE] mov dx,_8255_porta out dx,al ;mov al,0feh mov al, 011111110b mov dx,_8255_portb out dx,al call DELAY ;bit 1 mov al,[LED_CODE+1] mov dx,_8255_porta out dx,al ;mov al,0feh mov al, 011111101b mov dx,_8255_portb out dx,al call DELAY ;bit 2 mov al,[LED_CODE+2] mov dx,_8255_porta out dx,al ;mov al,0feh mov al, 011111011b mov dx,_8255_portb out dx,al call DELAY ;bit 3 mov al,[LED_CODE+3] mov dx,_8255_porta out dx,al ;mov al,0feh mov al, 011110111b mov dx,_8255_portb out dx,al call DELAY ;bit 4 mov al,[LED_CODE+4] mov dx,_8255_porta out dx,al ;mov al,0feh mov al, 011101111b mov dx,_8255_portb out dx,al call DELAY ;bit 5 mov al,[LED_CODE+5] mov dx,_8255_porta out dx,al ;mov al,0feh mov al, 011011111b mov dx,_8255_portb out dx,al call DELAY ;bit 6 mov al,[LED_CODE+6] mov dx,_8255_porta out dx,al ;mov al,0feh mov al, 010111111b mov dx,_8255_portb out dx,al call DELAY ;bit 7 mov al,[LED_CODE+7] mov dx,_8255_porta out dx,al ;mov al,0feh mov al, 001111111b mov dx,_8255_portb out dx,al call DELAY ret ;------------------------------------------ ;8255 key ;------------------------------------------ _8255_key: MOV DX,202H IN AL,DX TEST AL,01H JNZ NO_KEY ;INC KEY_CNT mov di, STR4 CALL STR_OUT NO_KEY: NOP ret ;STR_OUT ENDP STR1 DB 'i8088-HELLO boy or girl!' ,13,10,'$' STR2 DB 0AH,0DH,' ',0dh,0ah,'$' STR3 db 'ex005---8255 key demo',13,10,'$' STR4 db 'key0 event happen!',13,10,'$' LED_CODE db 0C0h,0F9h,0A4H,0B0H,99H,92H,82H,0F8H,80H,90H db 55h,55h,55h,55h,55h,55h ;程序结束标志，监控bios程序，收到后自动跳转到内存0000:2000处执行 ;----------------------------------------------------------------------------------------------
3.编译下载测试
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