system.asm

来自「给出了W29C040的驱动子程序」· 汇编 代码 · 共 23 行

.include hardware.inc;

.CODE
.public _System_Initial;
.public	F_System_Initial;
_System_Initial: .PROC
F_System_Initial:

		R1 = 0							
		[R_InterruptStatus] = R1		//中断状态标志
		[P_INT_Ctrl] = R1				//清所有中断
        
        R1 = 0x00F0             //IOA0--IOA3 接键盘，设置为输入
        [P_IOA_Dir] = R1        //IOA4--IOA7 接SRAM控制线，设置为输出
        [P_IOA_Attrib] = R1     //
        R1 = 0x00F0 
        [P_IOA_Data] = R1       
		retf;
		.ENDP;