ad_key.asm

减少单片机IO资源占用,采用AD口加电阻网点方式扩展按键.含汇编代码.

;==================================================================================
; The information contained herein is the exclusive property of
; Sunplus Technology Co. And shall not be distributed, reproduced,
; or disclosed in whole in part without prior written permission.
;       (C) COPYRIGHT 2004   SUNPLUS TECHNOLOGY CO.                                  
;                   ALL RIGHTS RESERVED
; The entire notice above must be reproduced on all authorized copies.
;==================================================================================
										
;==================================================================================
;	Project Name	:	
;	Applied Body	:	SPMC65P2404A
;	Firmware version:
;	Programer		:
;	Date			:	2005-1-19
;	Description		:	The Program presents how to scan 16 Keys with the function 
;						of ADC.
;						
;	Hardware Connect:	
;	Link File		:	
;	IDE Version		: 	V1.6.5	
;	BODY Version	:	V1.0.0A
;==================================================================================
.SYNTAX  6502							;Process standard 6502 addressing syntax
.LINKLIST								;Generate linklist information
.SYMBOLS								;Generate symbolic debug information
;**********************************************************************************
;constant
CB_CmpTimers		EQU		4			;The maximum times of compare
;**********************************************************************************
.PAGE0 
GB_KeyValue			DS		1			;Keys value	
GB_KeyDownFlag		DS		1			;Keys-down flag,"1" represents down.
IB_KeyupFlag		DS		1			;Keys-up flag,"0" represents up. 
IB_KeyValue			DS		1			;Keys value	for comparing
IB_CmpTimers		DS		1			;The times of comparing
.DATA
;**********************************************************************************
.CODE
;==================================================================================
;	Function:		F_ADKeyx16
;	Description:	Scanning 16 Keys
;	Input:			None
;	Output:			GB_KeyValue---------Keys value
;					GB_KeyDownFlag------Key-Down flag
;	Destroy:		A
;	Stacks:			1
;==================================================================================
F_ADKeyx16:
;----------------------------------------
;AD convert
;----------------------------------------
        lda     P_AD_Ctrl0              
        and		#11111110B				;start convert
        sta     P_AD_Ctrl0

L_TestAdcL2:
        lda     P_AD_Ctrl0
		and		#00000001B				;convertion OK ?
		beq		L_TestAdcL2				;no
		
		lda		IB_KeyupFlag			;Key up?
		bne		?L_JudgeUp				;No
		
?L_KeyCope:
		lda		P_AD_DataHi				;AD high 8bit value
		and		#$F						;\
		cmp		#$4						;+
		bcc		?L_CmpClr				;+ = The AD value exceed rang? yes	
		cmp		#$C						;+	 			 
		bcs		?L_Keyup				;/			
		
		lda		P_AD_DataHi
		and		#$F0
		cmp		IB_KeyValue				;Compare AD value with the last time
		beq		?L_Inc					;Equal?yes
		sta		IB_KeyValue
		jmp		?L_CmpClr		
?L_Inc:
		inc		IB_CmpTimers			;\		
		lda		IB_CmpTimers			;+ = 4-time Comparing end? no					
		cmp		#CB_CmpTimers			;+						
		bcc		?L_ADKeyx16Exit			;/			
		lda		IB_KeyValue				;\	
		lsr		a						;+
		lsr		a						;+ = Get the key value
		lsr		a						;+	
		lsr		a						;+	
		sta		GB_KeyValue				;/	
		lda		#1
		sta		GB_KeyDownFlag			;Set the Key-down flag
?L_Keyup:		
		lda		#1
		sta		IB_KeyupFlag			;Key not up 
		jmp		?L_CmpClr
		
?L_JudgeUp:
		lda		P_AD_DataHi			
		cmp		#$4						;Key up?
		bcs		?L_CmpClr				;No
		inc		IB_CmpTimers			;\
		lda		IB_CmpTimers			;+ = Compare 4 times untile all Keys up
		cmp		#CB_CmpTimers			;+ 
		bcc		?L_ADKeyx16Exit			;/
		lda		#0							
		sta		IB_KeyupFlag			;Keys up
?L_CmpClr:
		lda		#0
		sta		IB_CmpTimers		
?L_ADKeyx16Exit:		
		rts     
		       
;==================================================================================
;	Function:		F_Light
;	Description:	light LEDs to reflect the Keys value
;	Input:			GB_KeyValue------Keys value
;	Output:			none
;	Destroy:		A
;	Stacks:			1
;==================================================================================
.PUBLIC			F_Light
F_Light:
		lda		GB_KeyValue
		sta		P_IOC_Data		
		rts            
;==================================================================================
;	Function:		F_AD_KeyInit
;	Description:	initialize PC as output "0", set ADC
;	Input:			none
;	Output:			none
;	Destroy:		A
;	Stacks:			1
;==================================================================================
F_AD_KeyInit:
		lda		#0
		sta		P_IOC_Attrib
		sta		P_IOC_Data
		lda		#$FF
		sta		P_IOC_Dir

		lda     #(C_AD_CE+C_AD_Ch0)    	;Select channel 0 (AN0) 
        sta     P_AD_Ctrl2				

        lda     #(C_AD_EN+C_AD_CS_32)   ;Fcpu/32
        ora		#00000001B			
        sta     P_AD_Ctrl0				
        
        lda     #C_AD_Pin0 				;Analog input : channel 0 
        sta     P_AD_Ctrl1			

        rts            

;==================================================================================
;	Function:		F_Variable_Init
;	Description:	Initialize variables
;	Input:			none
;	Output:			none
;	Destroy:		A
;	Stacks:			1
;==================================================================================
F_Variable_Init:
        lda		#0
        sta		GB_KeyDownFlag				;Keys are not down in initial state 
        sta		IB_CmpTimers				;The times of compare is 0 in initial state
        sta		IB_KeyupFlag				;Keys are all up in initial state
		sta		GB_KeyValue					;Key value
		rts