init_ad50.asm.bak

采用TMS320VC5402实现一个16阶低通滤波器

			.include	regs.h
			.def	init_AD50
			

NOP_REQ		.set		0000h	; Pseudo reg0 val
REG1_RESET	.set		0180h	; reset ad50c register1  
REG1_VAL    .set       	0100h   ; INP & INM for DAC, 15+1bit mode DAC 
REG2_VAL	.set		0200h 	; unable telephonemode 
REG3_VAL	.set		0300h	; No delayed frame-sync
REG4_VAL	.set		0430h	; Fs = MCLK/(128*N) = 8.192E6/(128*6) 
					; Gain: Input=0dB, Output=0db
SEC_REQ		.set		0001h

			.text

;==========================================================
;	Initialize AD50 REG1, REG2, & REG4
;	Default val for AD50 REG3
;==========================================================
	
init_AD50:  		portr		DSP_CPLD_CNTL2, 60h 	; select on-board AD50
			nop
			nop
			andm		0FF00h, 60h
			portw		60h, DSP_CPLD_CNTL2
			nop
			nop
			
			stm		7FFFh,IFR			; clear BXINT1 flag	
			stm		0800h,IMR			; unmask BXINT1

			stm		SPCR2, McBSP1_SPSA	; enable McBSP1 Tx
			orm		0001h, McBSP1_SPSD	; wait 2 SCLK cycle
			nop
			nop
			nop
			nop
			
			LD #REG1_RESET,0,A
			CALLD WAIT
			NOP
            		NOP
            
			LD		#REG1_VAL,0,A		; ACCA=0x104 
			CALLD		WAIT				; send to AD50 
			nop
			nop
			LD		#REG2_VAL,0,A		; ACCA=0x210
			CALLD		WAIT				; send to AD50 
			nop
			nop						
			LD		#REG4_VAL,0,A		; ACCA=0x4F0
			CALLD		WAIT				; send to AD50 
			nop
			nop


			LD #REG3_VAL,A
			CALLD WAIT
			NOP
			NOP
			STM		SPCR2, McBSP1_SPSA	; disable McBSP1 Tx
			ANDM		0FFFEh, McBSP1_SPSD	; wait 2 SCLK cycle
			nop
			nop
		
                        RETD
                        nop
                        nop

WAIT:			STM 		SEC_REQ, McBSP1_DXR1	; McBSP1_DXR1=1
			nop
			STM		7FFFh,IFR			; clear BXINT1 flag
			nop					
			idle		1				; wait for BXINT1
		
			STLM		A,McBSP1_DXR1		; ACCA=>McBSP1_DXR1
			nop	
			STM		7FFFh,IFR			; clearBXINT1 flag
			nop			
			idle		1				; wait for BXINT1
			RETD						; return
			nop
			nop
			NOP
			NOP
			NOP