;******************************************************************************/
;三角波發生為：
;       ;           ;
;     ;   ;       ;   ; 
;   ;       ;   ;       ;
; ;           ;           ;


;要改出來的三角波發生為:
;       ;      ;     ;
;     ; ;    ; ;   ;
;   ;   ;  ;   ; ;
; ;     ;      ; 

;******************************************************************************/


         .width   80
         .length  55
		 .title "main program of asm for code generate"
         .mmregs
                  
         .global _Encoder
         .global BSP_SEND
         

BSP_TRANSMIT_ONLY	.set 0080H		;int control

;**********************************************************************/
;* 	          		Register of vc5416 MMR						      */
;**********************************************************************/
;MCBSP2 CONFIGURATION REGISTER NAME ADDRESS INDEX:
DXR1_2 	.set 33h
SPSA2	.set 34h
SPSD2	.set 35h
SPCR12	.set 00h
SPCR22	.set 01h
XCR12	.set 04h
XCR22	.set 05h
SRGR12	.set 06h
SRGR22	.set 07h
MCR22	.set 09h
XCERA2	.set 0Ah
XCERB2	.set 0Bh
PCR2	.set 0Eh

STEP	.set 0020h
LOW_LIM	.set 0101h
HIGH_LIM	.set 7EFFh
;HIGH_LIM	.set 3FFFh

	.data
COUNTER:	.word 0h
FLAG:		.word 0h	
    	.text
_Encoder:
		STM #01A0H,PMST			
		SSBX INTM
SETREG:	
     	RSBX INTM
		STM #BSP_TRANSMIT_ONLY,IFR
		STM #BSP_TRANSMIT_ONLY,IMR			
		STM SPCR22,SPSA2
		STM #0000000000000000B,SPSD2
			;000000					RSRV
			;~~~~~~1				FREE MODE
			;~~~~~~~0				NO SOFT MODE
			;~~~~~~~~0				FRAME SY RESET
			;~~~~~~~~~0				SAMPLE GENERATOR RESET
			;~~~~~~~~~~00			XINT BY XRDY(END-OF-WORD)
			;~~~~~~~~~~~~0			X SY ERROR		
			;~~~~~~~~~~~~~00		READ ONLY
			;~~~~~~~~~~~~~~~0		TXD	/RESET
		STM SPCR12,SPSA2				
		STM #0000000000000000B,SPSD2
			;0						NO DIG LOOP BACK
			;~01					接收符號擴展
			;~~~00					NO CLK STOP MODE
			;~~~~~000				RSRV
			;~~~~~~~~0				DX ENABLER
			;~~~~~~~~~0				A-BIS
			;~~~~~~~~~~00			R INT
			;~~~~~~~~~~~~0			R SY ERROR
			;~~~~~~~~~~~~~00		READ ONLY
			;~~~~~~~~~~~~~~~0		REC /RESET
		STM #XCR12,SPSA2
		STM #0000001101000000B,SPSD2
			;0						RSRV
			;~0000011				XFLEN=(3+1)WORD
			;~~~~~~~~010			WORD LENGTH 16BITS
			;~~~~~~~~~~~00000		RSRV
		STM #XCR22,SPSA2
		STM #0000001101000000B,SPSD2
			;0						SINGLE_PHASE
			;~0000011				XFLEN2
			;~~~~~~~~010			WORD LENGTH(16BIT)
			;~~~~~~~~~~~00			NO COMPANDING,MSB FIRST
			;~~~~~~~~~~~~~0			TRANS FRAME SY NOT IGNORED
			;~~~~~~~~~~~~~~00		0 BIT DELAY
		STM SRGR12,SPSA2
		STM #0001111100000000B,SPSD2
			;00011111				FRAME WIDTH 63+1=64
			;~~~~~~~~00000000		01H DIV FROM CLK TO SAMPLE GENERATOR
		STM SRGR22,SPSA2
		STM #0000000000011111B,SPSD2
			;00						SAMPLE GENERATOR CLK SY(NO USE IN INT CLK DRV)
			;~~0					SAMPLE GENERATOR CLK FROM EXT
			;~~~0					TRANSMIT SY IS DRIVEN BY DXR-XSR
			;~~~~000000011111		THE NEXT SY BECOMES ACTIVE 64 SAM_GEN PERIOD
		STM PCR2,SPSA2
		STM #0000000010000011B,SPSD2
			;00						RSRV
			;~~0					DX NOT USE AS A GPIO
			;~~~0					RX NOT USE AS A GPIO
			;~~~~00					SY IS GENRATE BY EXT CLK
			;~~~~~~00				CLKX/R IS GENERATE BY EXT CLK
			;~~~~~~~~0				RSRV
			;~~~~~~~~~000			READ ONLY
			;~~~~~~~~~~~~0011		TRANSMIT AT FALLING EDGE
		NOP
		NOP
		STM SPCR22,SPSA2
		STM #0000000100000001B,SPSD2
LOOP:	
		NOP
		NOP	
BUFFWREND:
		RET
 
BSP_SEND:
		LD	*(COUNTER),A			;讀取計數器
		AND #000000FFFFH,A			;取低16位
;		CMPM *(FLAG),#1H			;判斷上升沿
;		BC	FALL,TC				
		ADD	#STEP,A				;累加步長
		STL A,*(COUNTER)			;存計數器
		STLM A,DXR1_2				;送入串行發送寄存器
;		SUB	#HIGH_LIM,A,B			;判斷是否到達最高點
		CMPM *(COUNTER),#2000H			
		BC	STAYR,NTC			
		ST	#0000H,*(COUNTER)			;改變標志位，開始下降沿
STAYR:	RETE

;FALL:	SUB #STEP,A
;		STL A,*(COUNTER)			;存計數器
;		STLM A,DXR1_2				;送入串行發送寄存器
;		CMPM *(COUNTER),#8100H			;判斷是否到達最高點
;		SUB	#LOW_LIM,A,B
;		BC	STAYF,NTC
;		ST	#0,*(FLAG)			;改變標志位，開始下降沿
;STAYF:	RETE
		.end