CLR CLK
SETB CLK DJNZ R2,DP13 INC R0 DJNZ R1,DP12
RET
SEGTAB: DB 3FH,6,5BH,4FH,66H,6DH ;0，1，2，3，4，5
DB 7DH,7,7FH,6FH,77H,7CH ;6，7，8，9，A，B DB 58H,5EH,79H,71H,0,00H ;C，D，E，F，-
DELAY:
MOV R4,#80H AA1: MOV R5,#0FFH AA: NOP NOP
DJNZ R5,AA DJNZ R4,AA1 RET
;//******************************************************************* DAC0832 EQU 8000H
ORG 0000H LJMP START
ORG 0100H START:
MOV SP,#60H
MOV R0,#0 ;定义指向正弦DAC数据的指针，因为有361个数据
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MOV R1,#0 ;所以用了R0和R1两个寄寸器 LOOP:
MOV A,R0
MOV DPTR,#SINE_DATA CJNE R1,#1,LOW_TAB
INC DPH ;判断指针的高位字节R1是否为1。如果是，则DPH LOW_TAB: ;加1
MOVC A,@A+DPTR ;取出正弦波DAC的数据 MOV DPTR,#DAC0832
MOVX @DPTR,A ;启动D/A转换
INC R0 ;指针底八位加1处理 CJNE R1,#1,INC_LOW CJNE R0,#105,INC_OK
MOV R0,#0 ;如果已经取完数据并输出，则重新设置指针 MOV R1,#0 SJMP INC_OK INC_LOW:
CJNE R0,#0,INC_OK;判断是否要进位 MOV R1,#1 INC_OK:
ACALL DELAY AJMP LOOP
;********************************************** ;通过设置延时时间的长短来改变锯齿波的周期 ;********************************************** DELAY:
MOV R7,#5;改变数值可以改变正弦波的频率
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DJNZ R7,$ RET
;****************************** ;正弦波数据表，8位DAC的数据 ;****************************** SINE_DATA:
DB 128,130,132,135,137,139,141,144,146,148 DB 150,152,155,157,159,161,163,165,168,170 DB 172,174,176,178,180,182,184,186,188,190 DB 192,194,196,198,200,201,203,205,207,209 DB 210,212,214,215,217,219,220,222,223,225 DB 226,227,229,230,232,233,234,235,237,238 DB 239,240,241,242,243,244,245,246,247,247 DB 248,249,250,250,251,252,252,253,253,254 DB 254,254,255,255,255,255,255,255,255,255 DB 255,255,255,255,255,255,255,255,255,254 DB 254,254,253,253,252,252,251,250,250,249 DB 248,247,247,246,245,244,243,242,241,240 DB 239,238,237,235,234,233,232,230,229,227 DB 226,225,223,222,220,219,217,215,214,212 DB 210,209,207,205,203,201,200,198,196,194 DB 192,190,188,186,184,182,180,178,176,174 DB 172,170,168,165,163,161,159,157,155,152 DB 150,148,146,144,141,139,137,135,132,130 DB 128,126,124,121,119,117,115,112,110,108 DB 106,104,101,99,97,95,93,91,88,86 DB 84,82,80,78,76,74,72,70,68,66 DB 64,62,60,58,56,55,53,51,49,47
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DB 46,44,42,41,39,37,36,34,33,31 DB 30,29,27,26,24,23,22,21,19,18 DB 17,16,15,14,13,12,11,10,9,9 DB 8,7,6,6,5,4,4,3,3,2 DB 2,2,1,1,1,0,0,0,0,0 DB 0,0,0,0,0,0,1,1,1,2 DB 2,2,3,3,4,4,5,6,6,7 DB 8,9,9,10,11,12,13,14,15,16 DB 17,18,19,21,22,23,24,26,27,29 DB 30,31,33,34,36,37,39,41,42,44 DB 46,47,49,51,53,55,56,58,60,62 DB 64,66,68,70,72,74,76,78,80,82 DB 84,86,88,91,93,95,97,99,101,104 DB 106,108,110,112,115,117,119,121,124,126 DB 128 END
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