//========================================================================================
// Progarm: The head file for key.asm in assembly view
// Arranged by: Andy Hsu
// Modified by Arthur Shieh
// Last modified date: 
// 		2000/06/23: first version
//		2000/07/20: modified
//      2002/5/31 : Modified by Arthur Shieh to use IOA8~IOA15 for keyscan
//
// Functions:
//  F_Key_Scan_Initial;
//  F_Key_Scan_ServiceLoop;
//  F_Key_DebounceCnt_Down;
//
//	call F_SP_GetCh;		
//========================================================================================
.INCLUDE hardware.inc;
.public _F_Key_Scan_Initial
.PUBLIC	F_Key_Scan_Initial;
.public _F_Key_Scan_ServiceLoop
.PUBLIC F_Key_Scan_ServiceLoop;
.PUBLIC _SP_GetCh;
.PUBLIC	F_SP_GetCh;

.PUBLIC R_KeyStrobe;

.public _F_KeyScan;

.define Port_Key	P_IOA_Data					//Key input port
.define	Port_Key_A	P_IOA_Attrib
.define	Port_Key_D	P_IOA_Dir
.define	Port_Key_B	P_IOA_Buffer

.define M_MASK		0x00ff						//the port of the key input
.define M_ScanBegin	0x0001						//the begin bit of key scan
.define M_KeyNumber 0x0008						//key numbers
//////////////////////////////////////////////////////////////////
// RAM Define Area								
//////////////////////////////////////////////////////////////////
.RAM
.VAR	R_DebounceReg;						//for keyboard scan
//.DEFINE C_DebounceCnt			0x0008;		
.DEFINE C_DebounceCnt			0x0006;		
.VAR	R_KeyStrobe;						//for keyboard scan

.var R_KeyCounter							//key down counter
.var R_Keyflag								//save the key flag
.var R_Keyoll								//save the oll data of key

.CODE
//////////////////////////////////////////////////////////////////
// Function: Initialization for F_Key_Scan_ServiceLoop
//////////////////////////////////////////////////////////////////    
_F_Key_Scan_Initial: 
F_Key_Scan_Initial:
		r1 = [Port_Key_A]
		r1 = r1&(~M_MASK)
		[Port_Key_A] = r1
		r1 = [Port_Key_D]
		r1 = R1&(~M_MASK)
		[Port_Key_D] = r1
		r1 = [Port_Key_B]
		r1 = r1&(~M_MASK)
		[Port_Key_B] = r1
		
		r1 = 0x0000;					//
		[R_KeyCounter] = r1;			//
		[R_Keyflag] = r1; 				//
		[R_Keyoll] = 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 b15-b8
// Output: R_KeyStrobe b7-b0
//          | 	  |     |     | 
// +Vcc --- x --- x ... x --- x ---   
//          |     |     |     |
//          IOA.15            IOA.8
// Note: 1)link F_DebounceCntDown is necessary 
// Destory register: r1, r2                                            
////////////////////////////////////////////////////////////////// 
_F_Key_Scan_ServiceLoop:
F_Key_Scan_ServiceLoop:
		r1 = [Port_Key];			// get key data from IOA 
		r2 = M_MASK
		r1 &= R2
		jnz H_KeyHight				//非零轉
		r2 = [R_Keyoll]
		jnz L_KeyLow				//上一次的鍵值非零，則轉
		r1 = 0
		jmp L_KS_Exit2				//退出
L_KeyLow:
		r2 = [R_Keyflag]
		test r2,0x0001
		jnz L_KeyLow_1				//標志位非零則轉
		r2 = 0
		[R_KeyCounter] = r2
		[R_Keyflag] = r2
		[R_Keyoll] = r1
		r1 = 0
		jmp L_KS_Exit2				//退出
L_KeyLow_1:
		r2 = 0
		[R_KeyCounter] = r2
		[R_Keyflag] = r2
		r1 = [R_Keyoll]				//取上一次的鍵值
		r2 = 0
		[R_Keyoll] = r2
		jmp L_KeyGet				//到判斷優先級的程序
		
H_KeyHight:							//當次按鍵非零處理
		r2 = [R_KeyCounter]
		cmp r2,C_DebounceCnt 		//比較
		ja H_KeyHight_1				//大于規定數，轉
		r2+=1						//Counter++
		[R_KeyCounter] = r2
		jmp H_KeyHight_2
H_KeyHight_1:
		r2 = [R_Keyflag]			//flag 置位
		r2 |= 0x0001
		[R_Keyflag] = r2
H_KeyHight_2:
		[R_Keyoll] = r1
		r1 = 0
		jmp L_KS_Exit2				//退出    	
		
//L_KeyGet:
//		r2 = r1					//鍵盤優先級而做的 begin....
//		r3 = 0x0080				//Edit by xinqiang 2004.12.21
//L_KS_Renews2:					//xinqiang@sunnorth.com.cn
//		r3 = r3 lsl 1			//tel:010-62981668-2916
//		test r3,0x2000			//
//		jz L_KS_Renews12			//
//		r1 = 0					//
//		jmp L_KS_Exit2			//
//L_KS_Renews12:					//
//		r1 = r1&r3				//
	//	jnz L_KS_Exit2			//
L_KeyGet:
		jmp L_KS_Exit2
		r1 = r2					//
//		jmp L_KS_Renews2			//....end
L_KS_Exit2:
		[R_KeyStrobe] = r1;				//save stable key code to R_KeyStrobe
		retf;								//	


//****************************************************************
// Function: Get Keycode for I/O Port                                 
// Destory register: r1, r2                          
//****************************************************************
_SP_GetCh:					
F_SP_GetCh:
		push r2 to [SP];	  
		r1 = [R_KeyStrobe];				// Get Key code
        r2 = 0x0000;					// Clear KeyStrobe for next key	
        [R_KeyStrobe] = r2;				//
        pop	r2 from [SP];
        retf;

//=================================================================//
//name:F_KeyScan
//for user: C function unsigned int F_KeyScan(void)
//output:Key Sand data from Key1~5    Key1>>Key2>>Key3>>Key4>>Key5
//note: noll
//=================================================================//
_F_KeyScan:.proc
F_KeyScan:
	push r2,r5 to [sp]
	r1 = [Port_Key]
	r1 ^= M_MASK
	jnz F_KeyScan_Get1
	r1 = 0
	jmp F_KeyScan_Exit
F_KeyScan_Get1:
	call F_Delay				//call key Scan delay 10~18ms
	r1 = [Port_Key]
	r1 ^= M_MASK
	jnz F_KeyScan_Get2			//check the key again
	r1 = 0
	jmp F_KeyScan_Exit
F_KeyScan_Get2:
	r2 = r1
	r3 = r1
	r1 = 0
	r4 = M_ScanBegin  //0x0001
F_KeyScan_loop1:
	r1+=1
	r3 = r3&r4
	jnz F_KeyScan_Exit1
	cmp r1,M_KeyNumber  //8
	je F_KeyScan_Exit1
	r4 = r4 lsl 1
	r3 = r2
	jmp F_KeyScan_loop1
F_KeyScan_Exit1:
//	r1 = r3
F_KeyScan_Exit2:
	r3 = 0x0001
	[P_Watchdog_Clear] = r3
	r2 = [Port_Key]
	r2 ^= M_MASK
	jnz F_KeyScan_Exit2
F_KeyScan_Exit:
	pop r2,r5 from [sp]
	retf
.endp


F_Delay:
	push r3 ,r5 to [sp]
	r3=0x6e6d//0xDCDB
Dely_L:
	r4 = 0x0001
	[P_Watchdog_Clear] = r4
	r3-=1
	jnz Dely_L
	pop r3,r5 from [sp]
	retf
//========================================================================================        
// End of key.asm
//========================================================================================