www.pudn.com > 多命令语音识别范例.rar > Key.asm

.INCLUDE hardware.inc; 
 
.PUBLIC	F_Key_Scan_Initial; 
.PUBLIC _Key_Scan_ServiceLoop; 
.PUBLIC F_Key_Scan_ServiceLoop; 
 
.PUBLIC F_Key_DebounceCnt_Down; 
.PUBLIC _SP_GetCh; 
.PUBLIC	F_SP_GetCh; 
 
.PUBLIC R_KeyStrobe; 
 
////////////////////////////////////////////////////////////////// 
// RAM Define Area								 
////////////////////////////////////////////////////////////////// 
.RAM 
.VAR	R_DebounceReg;						//for keyboard scan 
.DEFINE C_DebounceCnt			0x0002;		 
 
.VAR	R_DebounceCnt;						//for keyboard scan 
.VAR	R_KeyBuf;							//for keyboard scan 
.VAR	R_KeyStrobe;						//for keyboard scan 
 
.CODE 
////////////////////////////////////////////////////////////////// 
// Function: Initialization for F_Key_Scan_ServiceLoop 
//////////////////////////////////////////////////////////////////      
_Key_Scan_ServiceLoop: 
F_Key_Scan_Initial: 
		r1 = 0x0000;					// 
		[R_DebounceReg] = r1;			// 
		[R_KeyBuf] = r1; 				// 
		[R_KeyStrobe] = r1;				// 
		r1 = C_DebounceCnt;				// 
		[R_DebounceCnt] = r1;			//reset debounce counter 
		retf; 
 
////////////////////////////////////////////////////////////////// 
// Function: Get Key code from key pad(8 x 1 key pad) 
// Input: Port IOA b7-b0 
// Output: R_KeyStrobe b7-b0 
//          | 	  |     |     |  
// +Vcc --- x --- x ... x --- x ---    
//          |     |     |     | 
//          IOA.7             IOA.0 
// Note: 1)link F_DebounceCntDown is necessary  
// Destory register: r1, r2                                             
//////////////////////////////////////////////////////////////////  
F_Key_Scan_ServiceLoop: 
		 
     	r1 = [P_IOA_Data];			// get key data from IOA    
    	//r1 = [P_IOB_Data];			// get key data from IOB 
	    	 
        r1 = r1 and 0xff;				// 
        r2 = [R_DebounceReg];			// 
        [R_DebounceReg] = r1;			// 
        cmp r2,[R_DebounceReg];			// 
        je	L_KS_StableTwoSample;		// 
         
        r1 = C_DebounceCnt;				//debounce time setting 
        [R_DebounceCnt] = r1;			// 
        retf;							// 
         
L_KS_StableTwoSample: 
		r1 = [R_DebounceCnt];			// 
		jz	L_KS_StableOverDebounce;	// 
		retf; 
	 
L_KS_StableOverDebounce:         
		[R_DebounceCnt] = r1;			// 
		r2 = [R_DebounceReg];			// 
		r1 = [R_KeyBuf];				// 
		[R_KeyBuf] = r2;				// 
		r1 = r1 xor 0x00ff;				// 
		r1 = r1 and [R_KeyBuf];			// 
		r1 = r1 and 0x00ff;				// 
		r1 = r1 or [R_KeyStrobe];		// 
		[R_KeyStrobe] = r1;				//save stable key code to R_KeyStrobe 
		retf;		 
	 
////////////////////////////////////////////////////////////////// 
// Function: debounce counter down count 
////////////////////////////////////////////////////////////////// 
F_Key_DebounceCnt_Down: 
		r1 = [R_DebounceCnt];			// Debounce subroutine for F_IO_Key_Scan: 
		jz	L_DebounceCntZero;			// stop count if zero 
		r1 -= 0x0001;					// 
		[R_DebounceCnt] = r1;			// 
L_DebounceCntZero:						// 
		retf;  							//	 
 
 
//**************************************************************** 
// Function: Get Keycode for I/O Port                                  
// Destory register: r1, r2                           
//**************************************************************** 
_SP_GetCh:					 
F_SP_GetCh: 
		//push	BP,BP to [SP]; 
  		//BP = SP + 1; 
		   
		r1 = [R_KeyStrobe];				// Get Key code 
        r2 = 0x0000;					// Clear KeyStrobe for next key	 
        [R_KeyStrobe] = r2;				// 
        //pop		BP,BP from [SP]; 
        retf; 
 
 
//========================================================================================         
// End of key.asm 
//========================================================================================