keyscan.asm

midi file with midi play.it can run in the computer

//-----------------------------------------------------------------------
//Program Name:		KeyScan.ASM
//Applied Body:		SPT6604Aretf
//Project Description:	This is a simple demo code for key scan.
//Compile:		Sunplus u'nSP IDE
//Programmer:		WangXu
//Current Version:	V1.0
//Written Date:		2002/10/30
//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
.RAM
KeyScanFlag:		.DW	0 //b0~b7 - read portA buffer
				//b8~11 - state machine
				//b12~15 - current scan line

KeyStatusBuf:		.DW	0,0,0,0,0
				//5 words - for key status
				//the high byte represents corresponding key is changed from 'released' to 'pressed'
				//the low byte represents corresponding key is pressed

KeyQueueBufPtr:		.DW	0 //b0~3 - read pointer
				//b4~7 - writer pointer
				//b8~11 - key queue size in use
				//b12~15- Key Bounce Timer
.const	KeyDebounceTime	=	3*8192;		//( 3/512Hz = 6ms)

KeyQueueBuf:		.DW	0,0,0,0
//-----------------------------------------------------------------------
.code
F_KeyTimerService:
	r1 =	[KeyQueueBufPtr]  
	test	r1,0xE000
	jz	?L_KeyTimeOver
	r1-=	0x2000
	[KeyQueueBufPtr] = r1 
?L_KeyTimeOver:
	retf

//*****************************************************************************/
// Purpose : Keyboard Scanner State Machine                                   */
//                 F_StartKeyScan                                             */
//                        \|/      F_ReScanKey <-----+                        */
//                 Scan R-option   (F_KeyCodeMapping)|                        */
//                        \|/         \|/            |                        */
//                 +---> F_PrepareNextScanLine       |                        */
//                 |          \|/                    |                        */
//                 |     F_ReadKeyBeforeBounce       |                        */
//                 |          \|/                    |                        */
//                 |     F_ReadKeyAfterBounce        |                        */
//                 |          \|/                    |                        */
//                 |     F_NextScanLine              |                        */
//                 | no       \|/               yes  |                        */
//                 +---- the last scan line ? -------+                        */
//*****************************************************************************/
//-----------------------------------------------------------------------
// State and vector definitions for keyboard scan
// The format is as follows:
// V_StateVector	   .DW      Address of Subroutine
// .const  S_StateName	      = State Number
V_KeyScan:
V_ReadKeyBeforeBounce:     .DW      F_ReadKeyBeforeBounce
.const   S_ReadKeyBeforeBounce      = (V_ReadKeyBeforeBounce-V_KeyScan)*256
V_ReadKeyAfterBounce:      .DW      F_ReadKeyAfterBounce
.const   S_ReadKeyAfterBounce       = (V_ReadKeyAfterBounce-V_KeyScan)*256
V_KeyCodeMapping:	  .DW      F_KeyCodeMapping
.const   S_KeyCodeMapping	   = (V_KeyCodeMapping-V_KeyScan)*256
//----------------------------------------------------------------------------//
F_KeyScan:
	r1 =	[KeyScanFlag]
	r1 =	r1 lsr 4
	r1 =	r1 lsr 4
	r1&=	0x000F
	r1+=	V_KeyScan
	pc =	[r1]
//----------------------------------------------------------------------------//
F_ReadKeyBeforeBounce:	      		//the first read
	r1 =	[P_IOA_Data]
	r1^=	0x001F
	r1&=	0x001F			//b0~4 of r1 is result
	r2 =	[KeyScanFlag]
	r2&=	0xF000
	r2|=	S_ReadKeyAfterBounce
	[KeyScanFlag] = r2|r1
	r1 =	[KeyQueueBufPtr]     //send debounce time
	r1&=	0x1FFF
	r1|=	KeyDebounceTime
	[KeyQueueBufPtr] = r1
	retf
//----------------------------------------------------------------------------//
F_ReadKeyAfterBounce:			//the second read after bounce time
	r1 =	[KeyQueueBufPtr]
	test    r1,0xE000
	jz      ?L_BounceTimeOut
	goto	?L_ReadKeyOver
?L_BounceTimeOut:
	bp =	P_IOA_Data
	r1 =	[bp]
	r1^=	0x001F
	r1&=	0x001F			//b0~4 of R1 is result
	r2 =	[KeyScanFlag]
	r3 =	r2 & 0x001F
	cmp     r1,r3
	jnz	?L_KeyStatusOk		//ignore, not equal
	bp =	r2 lsr 4
	bp =	bp lsr 4
	bp =	bp lsr 4		//the current scan line
	bp+=	KeyStatusBuf
	r3|=	[bp]
	r3^=	[bp]			//'0' -- '1',the corresponding bit is '1'
	r3 =	r3 LSL 4
	r1|=	r3 LSL 4
	[bp]	= r1
?L_KeyStatusOk:
	r1 =	[KeyScanFlag]
	r1+=	0x1000
	r1&=	0xF000
	cmp	r1,0x5000		//have all lines scanned?
	jge	?L_KeyScanLineOver	//check key and scan again
	r1|=	S_ReadKeyBeforeBounce	//check next line
	[KeyScanFlag] = r1
?L_PrepareNextScanLine:
	r1 =	r1 lsr 4
	r1 =	r1 lsr 4
	r1 =	r1 lsr 4
	r1+=	TW_ScanLine
	r1 =	[r1]
	int	off
	r2 =	[P_IOB_Buf]
	r2&=	0x00E0
	r2|=	r1
	[P_IOB_Data] = r2		  //Set scan line
	int	fiq,irq
	jmp	?L_ReadKeyOver
?L_KeyScanLineOver:
	r1 |= S_KeyCodeMapping
	[KeyScanFlag] = r1
?L_ReadKeyOver:
	retf
//-------------------------------------------------------------------------------
TW_ScanLine:
	.DW      0x001F - 0x0001	// IOB0 = 0
	.DW      0x001F - 0x0002	// IOB1 = 0
	.DW      0x001F - 0x0004	// IOB2 = 0
	.DW      0x001F - 0x0008	// IOB3 = 0
	.DW      0x001F - 0x0010	// IOB4 = 0
//----------------------------------------------------------------------------//
F_KeyCodeMapping:
	r1 =	0x0000			//r1 - column number
?L_SearchKeyLoop:
	bp =	r1+KeyStatusBuf
	r2 =	[bp]
	test	r2,0x1F00
	jnz	?L_FindKeyChanged	//key is changed to be pressed from release
	r1+=	0x0001
	cmp	r1,0x0005
	jl	?L_SearchKeyLoop
	goto	?L_ReStartScanKey
?L_FindKeyChanged:			//r1 - column number
	r3 =	r2 lsr 4
	r3 =	r3 lsr 4
	r3&=	0x001F
	r3^=	0x001F
	r3&=	r2
	jz	?L_ChangePressSameKey
	goto	?L_ReStartScanKey
?L_ChangePressSameKey:
//----------------------------------------------------------------------------
//Check if other key is pressed
	r4 = KeyStatusBuf
?L_SearchOtherKeyLoop:
	cmp	r4,bp
	jz      ?L_SearchNextLine
	r3 =	[r4]
	test    r3,0x001F
	jz	?L_SearchNextLine
	goto	?L_ReStartScanKey	//other key is still pressed
?L_SearchNextLine:
	r4+=	0x0001
	cmp     r4,KeyStatusBuf+0x0005
	jl	?L_SearchOtherKeyLoop
//----------------------------------------------------------------------------
	bp =	TB_KeyNumber		//r2 - key status buffer's value
	bp+=	r1
	r3 =	[bp]
	r2&=	0x1F00
	r2 =	r2 LSL 2
?L_GetRowNumberLoop:
	r3-=	0x0001
	r2 =	r2 LSL 1
	jpl	?L_GetRowNumberLoop
	test	r2,0x7FFF
	jz	?L_NoOtherKey
	goto	?L_ReStartScanKey
?L_NoOtherKey:
	r3+=	TB_KeyCode
	r1 =	[r3]			//get key_code

	r2 = [KeyQueueBufPtr]
	test    r2,0x0800
	jnz	?L_ReStartScanKey	//KeyQueueBuf is full
?L_KeyBufNotFull:
	r2 =	r2 lsr 4
	r2&=	0x0007			//write pointer
	r3 =	r2 lsr 1
	r3+=	KeyQueueBuf
	r4 =	[r3]
	test    r2,0x0001
	jz      ?L_SaveKeyLowByte
	r4&=	0x00FF
	r1 =	r1 LSL 4
	r1 =	r1 LSL 4
	jmp     ?L_KeyValueIsOk
?L_SaveKeyLowByte:
	r4&=	0xFF00
?L_KeyValueIsOk:
	r1|=	r4
	[r3]	= r1			//store key
	r1 =	[KeyQueueBufPtr]
	r1+=	0x0110			//increase writer pointer & size
	r1&=	0xFF7F
	[KeyQueueBufPtr] = r1
?L_ReStartScanKey:
	call    F_ClrKeyStatusBuf
	r1 = S_ReadKeyBeforeBounce	//initialize KeyScanFlag
	[KeyScanFlag] = r1		//scan from R-option line
	r1 =	TW_ScanLine
	r1 =	[r1]
	int	off
	r2 =	[P_IOB_Buf]
	r2&=	0x00E0
	r2|=	r1
	[P_IOB_Data] = r2		//Set scan line
	int	fiq,irq
	retf
//-------------------------------------------------------------------------------
TB_KeyNumber:
	.DW    5
	.DW    10
	.DW    15
	.DW    20
	.DW    25
//-------------------------------------------------------------------------------
TB_KeyCode:
         .DW      C_One,      C_Two,   C_Three, C_Redial, C_Check;
         .DW      C_Four,     C_Five,  C_Six,   C_Pause,  C_Vip;   
         .DW      C_Seven,    C_Eight, C_Nine,  C_Store,  C_Hold;  
         .DW      C_Star,     C_Zero,  C_Pound, C_Flash,  C_Review;
         .DW      C_HandFree, C_Up,    C_Down,  C_Delete, C_Dummy;
//-------------------------------------------------------------------------------
//                  IOB0      IOB1     IOB2       IOB3       IOB4     
//              +----------+--------+--------+-----------+-----------+
//        IOA0  |    1     |   2    |   3    |Redial/Auto| Check     |
//              +----------+--------+--------+-----------+-----------+
//        IOA1  |    4     |   5    |   6    |Pause/Inhib|  VIP      |
//              +----------+--------+--------+-----------+-----------+
//        IOA2  |    7     |   8    |   9    |   Store   |Hold       |
//              +----------+--------+--------+-----------+-----------+
//        IOA3  | * / P->T |   0    |   #    |Flash/Clear|Review/Next|
//              +----------+--------+--------+-----------+-----------+
//        IOA4  | HandFree |   Up   |  Down  |   Delete  |   Dummy   |
//              +----------+--------+--------+-----------+-----------+
//
//-------------------------------------------------------------------------------
F_StartKeyScan:				//initialize key scan
	r1 = 0				//clear KeyStatusBuf
	[KeyQueueBufPtr] = r1	//clear KeyQueueBufPtr
	call    F_ClrKeyStatusBuf
	r1 = S_ReadKeyBeforeBounce	//initialize KeyScanFlag
	[KeyScanFlag] = r1		//scan from R-option line
	r1 =	TW_ScanLine
	r1 =	[r1]
	r2 =	[P_IOB_Buf]
	r2&=	0x00E0
	r2|=	r1
	[P_IOB_Data] = r2		//Set scan line
	retf
//-------------------------------------------------------------------------------
F_ClrKeyStatusBuf:
	bp =	KeyStatusBuf
	r1 =	0x00FF
?L_ClrBufLoop:
	r2 =	[bp]
	r2&=	r1
	[bp++]	= r2
	cmp	bp,KeyStatusBuf+5
	jb	?L_ClrBufLoop
	retf
//-----------------------------------------------------------------------
//Key code constants
.const   C_Dummy           =0x0000;
.const   C_One             =0x0001;
.const   C_Two             =0x0002;
.const   C_Three           =0x0003;
.const   C_Four            =0x0004;
.const   C_Five            =0x0005;
.const   C_Six             =0x0006;
.const   C_Seven           =0x0007;
.const   C_Eight           =0x0008;
.const   C_Nine            =0x0009;
.const   C_Zero            =0x000A;
.const   C_Star            =0x000B;
.const   C_Pound           =0x000C;

.const   C_Pause           =0x000D;
.const   C_Flash           =0x001F;

.const   C_Redial          =0x0020;
.const   C_Store           =0x0021;
.const   C_Up              =0x0023;
.const   C_Down            =0x0024;
.const   C_Recall          =0x0026;
.const   C_Review          =0x0027;
.const   C_Hold            =0x0028;
.const   C_HandFree        =0x0029;
.const   C_Delete          =0x002A;
.const   C_Vip             =0x002C;
.const   C_Check           =0x0032;
//-----------------------------------------------------------------------