ex04.asm

这是一份学习DSP很有价值的PDF格式的课件

***定时器实验***


		.title	"ex4"
		.global	_c_int00
		.mmregs

ExNo	.set	00h
PERSEC	.set	01h
SEC		.set	02h
MIN		.set	03h
STATUS	.set	04h

TMP0	.set	64h
TMP1	.set	65h
TMP		.set	66h

		
		.sect	".vectors"
rst:	B		_c_int00
		NOP
		NOP
		.space	18*4*16

tint:	B		timeout
		NOP
		NOP
		.space	12*4*16
		
		.text
_c_int00
		LD 		#020h,DP				;置数据页指针
		STM		#3000h,SP
		SSBX	INTM
		RSBX	SXM
		STM		#07FFFh,SWWSR
		stm		#0001h,2Bh
		stm		#00a8h,PMST				;改变中断向量映射到0x0080
		
		STM		#1007h,CLKMD
		BITF 	CLKMD,#1h
		RPT 	#0FFh
		NOP
		NOP
		ST		#0004H,ExNo
		
		STM		#19999,PRD
		STM 	#0039h,TCR
		STM		#0FFFFh,IFR
		STM 	#0008h,IMR
		RSBX 	INTM

		ST 		#0,PERSEC
		ST 		#0,SEC
		ST 		#0,MIN
		ST 		#1,STATUS
		nop
		nop
		nop
		nop

		LDM		TCR,A
		AND 	#0FFEFH,A
		STLM	A,TCR

susp	nop
		nop
		nop
		B 		susp
		
timeout ADDM 	#1,PERSEC
		NOP
		NOP
		NOP
		NOP
        LD 		#100,A
        NOP
        NOP
        SUB 	PERSEC,A
        BC 		secout,ALEQ
        B 		exit
secout	ST 		#0,PERSEC
        ADDM 	#1,SEC
		LD 		#60,A
		SUB 	SEC,A
		BC 		minout,ALEQ
		B 		exit
minout	ST 		#0,SEC
		ADDM 	#1,MIN
		LD 		#100,A
		SUB 	MIN,A
		BC 		overflow,ALEQ
		B 		exit
overflow
		ST 		#0,MIN
		ORM 	#0030h,TCR		;Stop and Reload Timer
		ST 		#0,STATUS		;Set stopfalg
		
exit
		RETE
		
restart ST 		#0,PERSEC
		ST 		#0,SEC
		ST 		#0,MIN

		ANDM 	#0FFEFh,TCR
		RETE		

		.end