PIC单片机应用开发典型模块第八章程序.doc

PIC单片机应用开发典型模块第八章程序822020年4月19日资料内容仅供参考，如有不当或者侵权，请联系本人改正或者删除。( 1) 1616位定点数加、 减法程序LISTp=16f877INCLUDEp16f877.incACCALOEQU20;存放加数或减数低8位ACCAHIEQU21 ;存放加数或减数高8位ACCBLOEQU23 ;存放被加数或被减数低8位ACCBHIEQU24 ;存放被加数或被减数高8位ORG0X0000STARTGOTOMAIN; *双字节减法子程序, 入口地址ACCB-ACCA, 出口地址ACCB*D_subCALLNEG_A ;求ACCA的补码;双字节加法子程序, 入口地址ACCB+ACCA, 出口地址ACCBD_addMOVFACCALO, 0 ;ACCB和ACCA低半字节相加ADDWFACCBLOBTFSCSTATUS, C ;有进位否? INCFACCBHI ;有,ACCB高字节加1,再加ACCAHIMOVFACCAHI, 0 ;ACCA、 ACCB高半字节相加ADDWFACCBHIRETURN ;子程序返回;ACCA取补子程序NEG_ACOMFACCALO;ACCALO取反加1INCFACCALOBTFSCSTATUS, Z;低8位有进位吗? DECFACCAHI ;有, ACCAHI减1, 再取反COMFACCAHI ;否则ACCAHI直接取反RETURN ;子程序返回( 2) 1616位定点数乘法程序LISTp=16f877INCLUDEp16f877.incACCALOEQU20;存放乘数低8位ACCAHIEQU21;存放乘数高8位ACCBLOEQU23 ;存放被乘数低8位和乘积第1623位ACCBHIEQU24 ;存放被乘数高8位和乘积第2431位ACCCLOEQU26 ;存放乘积低8位ACCCHIEQU27 ;存放乘积高8位ACCDLOEQU28;临时寄存器ACCDHIEQU29;临时寄存器TEMPEQU2A;临时寄存器SIGNEQU2B ;存放乘积的符号ORG0X0000STARTGOTOMAINORG0X0100D_mpyCALLS_SIGN ;求取乘积的符号, 并对负数取补CALLSETUP ;调用子程序, 将ACCB的值送ACCDINCFTEMPCLRFACCCHI;清ACCCCLRFACCCLOMLOOPBCFSTATUS, C;清进位位RRFACCDHI;ACCD右移RRFACCDLOBTFSCSTATUS, C;判断是否需要相加CALLD_add ;加乘数至ACCB, 见加法程序BCFSTATUS, C;清进位位RRFACCBHI ;右移部分乘积RRFACCBLORRFACCCHIRRFACCCLODECFSZTEMP;乘法完成否? GOTOMLOOP;否, 继续求乘积BTFSSSIGN, 7 ;是, 确定乘积的符号GOTOOVER ;为正, 乘法结束COMFACCCLO ;为负, 乘积取补INCFACCCLOBTFSCSTATUS, ZDECFACCCHICOMFACCCHIBTFSCSTATUS, ZNEG_BDECFACCBLOCOMFACCBLOBTFSCSTATUS, ZDECFACCBHICOMFACCBHIOVERRETURN;子程序返回SETUPMOVLW15;初始化TEMP寄存器MOVWFTEMPMOVFACCBHI, 0 ;ACCB送ACCDMOVWFACCDHIMOVFACCBLO, 0MOVWFACCDLOCLRFACCBHI;清ACCBCLRFACCBLORETURN;子程序返回S_SIGNMOVFACCAHI, 0;ACCAHI异或ACCBHI, 结果送SIGN单元XORWFACCBHI, 0MOVWFSIGNBTFSSACCBHI, 7 ;ACCB为负吗? GOTOCHEK_A ;否, 检查ACCACALLNEG_B ;是, 求取ACCB绝对值CHEK_ABTFSCACCAHI, 7;ACCA为负吗? CALLNEG_A ;ACCA为负, 求取ACCA绝对值, RETURN ;ACCA和ACCB均为正, 返回( 3) 1616位定点数除法程序LISTp=16f877INCLUDEp16f877.incACCALOEQU20;存放除数低8位ACCAHIEQU21;存放除数高8位ACCBLOEQU22 ;存放被除数和商的低8位ACCBHIEQU23 ;存放被除数和商的高8位ACCCLOEQU24;存放余数低8位ACCCHIEQU25;存放余数高8位ACCDLOEQU26 ;临时寄存器ACCDHIEQU27 ;临时寄存器TEMPEQU28 ;临时寄存器SIGNEQU29;存放商的符号ORG0X0000STARTGOTOMAINORG0X0100D_divCALLS_SIGN;确定商的符号, 并将负数取补CALLSETUP ;初始化TEMP, 将被除数移至ACCDINCFTEMPCLRFACCCHI;清余数寄存器CLRFACCCLODLOOPBCFSTATUS, C ;清进位位RLFACCDLO ;被除数、 余数左移1位RLFACCDHIRLFACCCLORLFACCCHIMOVFACCAHI, 0 ;ACCCHI-ACCAHISUBWFACCCHI, 0BTFSSSTATUS, Z;ACCCHI=ACCAHI? GOTONOCHKMOVFACCALO, 0;是, ACCCLO-ACCALOSUBWFACCCLO, 0NOCHKBTFSSSTATUS, C;ACCCACCA? GOTONOGOMOVFACCALO, 0 ;是, 余数减除数SUBWFACCCLOBTFSSSTATUS, CDECFACCCHIMOVFACCAHI, 0SUBWFACCCHIBSFSTATUS, C ;置进位位NOGORLFACCBLO ;商左移1位RLFACCBHIDECFSZTEMP ;循环完毕? GOTODLOOPBTFSSSIGN, 7 ;是, 确定商的符号GOTODIVOVER ;为正, 除法结束, 跳转到结束行COMFACCCLO ;为负, 商和余数分别取补INCFACCCLOBTFSCSTATUS, ZDECFACCCHICOMFACCCHICALLNEG_B;见乘法程序中间NEG_BDIVOVERRETURN ;子程序返回S_SIGNMOVFACCAHI, 0;ACCAHI异或ACCBHI, 结果送SIGN单元XORWFACCBHI, 0MOVWFSIGNBTFSSACCBHI, 7 ;ACCB为负? GOTOCHEK_A ;否, 检查ACCACOMFACCBLO ;是, ACCB取补INCFACCBLOBTFSCSTATUS, ZDECFACCBHICOMFACCBHICHEK_ABTFSCACCAHI, 7;ACCA为负? CALLNEG_A ;ACCA为负, 取补( NEG_A子程序请参见 ;1616位定点数乘法子程序NEG_A) RETURN ;ACCA和ACCB均为负, 返回( 4) 浮点数加减法程序LISTp=16f877INCLUDEp16f877.incACCALOEQU20;存放加数或减数的尾数ACCAHIEQU21EXPAEQU22 ;存放加数或减数阶码ACCBLOEQU23 ;存放被加数或被减数尾数以及和或差ACCBHIEQU24EXPBEQU25 ;存放被加数或被减数阶码ACCCLOEQU26 ;临时寄存器ACCCHIEQU27 ;临时寄存器ACCDLOEQU28 ;临时寄存器ACCDHIEQU29 ;临时寄存器TEMPEQU2A ;临时寄存器TEMP1EQU30 ;临时寄存器TIMESEQU31 ;临时寄存器ORG0X000STARTGOTOMAINORG0X0100F_subCALLNEG_A;求ACCA的补码, 将减法转换为补码加法F_addCALLSUBADJ;调子程序判断EXPB和EXPA的大小BTFSCSTATUS, Z;参与运算的两个数阶码相等? GOTOPADD;是, 求尾数的和BTFSCSTATUS, C;EXPBEXPA? CALLF_swap;是, ACCB与ACCA互换MOVFEXPA, 0;否, 求取两者的差值SUBWFEXPBSCLOOPCALLSHFTSR;ACCB右移规格化INCFSZEXPB;EXPBEXPA? GOTOSCLOOP;否, 继续右移MOVFEXPA, 0;是, 存和( 差) 的阶码MOVWFEXPBPADDMOVFACCAHI, 0;ACCAHI或ACCBHIIORWFACCBHI, 0MOVWFSIGN;存于SIGN寄存器MOVFACCBHI, 0;暂存ACCBHIMOVWFEXPACALLD_add;尾数相加BTFSSSIGN, 7;ACCA和ACCB有负数? BTFSCACCBHI, 7;否, 把和的最高位和次高位同时进位? GOTOADD2;否, 转ADD2BTFSSACCAHI, 7;ACCA为负吗? GOTOADD3;ACCA和ACCB不同时为负, 转ADD3BTFSSEXPA, 7;是, ACCB为负吗? GOTOADD3BSFSTATUS, C;ACCA和ACCB同为负, 带负号右移RRFACCBHIRRFACCBLOINCFEXPBADD3CLRFACCCHI;和( 差) 规格化CLRFACCCLOCALLF_normRETURN;子程序返回ADD2BCFSTATUS, C;最高位次高位不同时进位, ACCB右移INCFEXPBGOTOSHFTRSHFTSRBCFSTATUS, C;ACCB带符号右移子程序BTFSCACCBHI, 7BSFSTATUS, CSHFTRRRFACCBHIRRFACCBLORETURN;子程序返回F_swapMOVFACCAHI, 0;ACCAHI、 ACCBHI互换MOVWFTEMPMOVFACCBHI, 0MOVWFACCAHIMOVFTEMP, 0MOVWFACCBHIMOVFACCALO, 0;ACCALO、 ACCBLO互换MOVWFTEMPMOVFACCBLO, 0MOVWFACCALOMOVFTEMP, 0MOVWFACCBLOMOVFEXPA, 0;EXPA、 EXPB互换MOVWFTEMPMOVFEXPB, 0MOVWFEXPAMOVFTEMP, 0MOVWFEXPBRETURNSUBADJMOVFEXPA, 0;EXPA异或EXPB, 结果送C_DIVXORWFEXPB, 0MOVWFC_DIVMOVFEXPA, 0;EXPB-EXPASUBWFEXPB, 0BTFSSC_DIV, 7;EXPA和EXPB同号? RETURN;是, 进位位的值真确反映两者的大小, 返回BTFSSSTATUS, C;否, 进位位的值取反GOTOCHANGECBCFSTATUS, CRETURNCHANGECBSFSTATUS, CRETURNF_normMOVFACCBHI;ACCB0? BTFSSSTATUS, ZGOTOC_normMOVFACCBLOBTFSCSTATUS, ZRETURN;是, 不需规格化, 返回C_normBTFSCACCBHI, 7;否。ACCB为负? GOTOC_norm2C_norm1BTFSC ACCBHI, 6;为正。规格化完毕? RETURN;ACCBHI.6=1, 规格化结束CALLSHFTSL;否。ACCB左移DECFEXPB;EXPB减1GOTOC_norm1;重新判断规格化完毕否? C_norm2BTFSSACCBHI, 6;ACCB为负。规格化完毕否? RETURN;ACCBHI.6=0, 规格化结束BCFSTATUS, CCALLSHFTSL;否, ACCB左移BSFACCBHI, 7;加符号DECFEXPB;EXPB减1GOTOC_norm2;重新判断规格化完毕否? SHFTSLBCFSTATUS, C;ACCB左移子程序RLFACCCLORLFACCCHIRLFACCBLORLFACCBHIRETURN( 5) 浮点数乘法程序LISTp=16f877INCLUDEp16f877.incACCALOEQU20;存放乘数尾数ACCAHIEQU21EXPAEQU22;存放乘数阶码ACCBLOEQU23 ;存放被乘数尾数和乘积高16位ACCBHIEQU24EXPBEQU25;存放被乘数阶码ACCCLOEQU26 ;存放乘积低16位ACCCHIEQU27ACCDLOEQU28;临时寄存器ACCDHIEQU29;临时寄存器TEMPEQU2A;临时寄存器TEMP1EQU30;临时寄存器TIMESEQU31;临时寄存器SIGNEQU2B;存放乘积符号COUNTEQU2F ;临时寄存器ACCEHIEQU30;临时寄存器ACCELOEQU31;临时寄存器ORG0X0000STARTGOTOMAINORG0X0100F_mpyCALLS_SIGN;求取乘积的符号, 并对负数取补CALLSETUP ;调用子程序将ACCB的值送ACCDCLRFACCCHI ;清ACCCCLRFACCCLOMLOOPBCFSTATUS, C;清进位位RRFACCDHI;ACCD右移RRFACCDLOBTFSCSTATUS, C ;判断是否需要相加CALLD_add ;加乘数至ACCBBCFSTATUS, C;清进位位RRFACCBHI;右移部分乘积RRFACCBLORRFACCCHIRRFACCCLODECFSZTEMP;乘法完成否? GOTOMLOOP;否, 继续循环MOVFEXPA, 0 ;是, 乘数与被乘数阶码相加, 得积的阶码ADDWFEXPBMOVFACCBHI;ACCBHI=0? BTFSSSTATUS, ZGOTOFINUP;否, 转FINUPMOVFACCBLO;ACCB0? BTFSSSTATUS, ZGOTOSHFT08 ;否, 只有ACCBHI=0, 转SHFT08MOVFACCCHI, 0 ;ACCB=0, 将乘积左移15位MOVWFACCBHIMOVFACCCLO, 0MOVWFACCBLOBCFSTATUS, CRRFACCBHIRRFACCBLOMOVLW.15;乘积阶码减15( 十进制数) SUBWFEXPBGOTOFINUPSHFT08MOVFACCBLO, 0;只有ACCBHI0, 乘积左移7位MOVWFACCBHIMOVFACCCHI, 0MOVWFACCBLOBCFSTATUS, CRRFACCBHIRRFACCBLOMOVLW.7;乘积阶码减7SUBWFEXPBFINUPCALLF_norm ;对乘积进行规格化BTFSSSIGN, 7;确定乘积的符号GOTOOVER ;为正, 乘法结束COMFACCCLO;为负, 乘积取补INCFACCCLOBTFSCSTATUS, ZDECFACCCHICOMFACCCHIBTFSCSTATUS, ZNEG_BDECFACCBLOCOMFACCBLOBTFSCSTATUS, ZDECFACCBHICOMFACCBHIOVERRETURN;乘法结束, 子程序返回S_SIGNMOVFACCAHI, 0 ;ACCAHI异或ACCBHI, 结果送SIGNXORWFACCBHI, 0MOVWFSIGNBTFSSACCBHI, 7;ACCB为负? GOTOCHEK_A;否, 检查ACCACOMFACCBLO;是, ACCB取补INCFACCBLOBTFSCSTATUS, ZDECFACCBHICOMFACCBHICHEK_ABTFSCACCAHI, 7;ACCA为负? CALLNEG_A;ACCA取补RETURN ;返回F_normMOVFACCBHI;ACCB0? BTFSSSTATUS, ZGOTOC_normMOVFACCBLOBTFSCSTATUS, ZRETURN ;是, 不需规格化, 返回C_normBTFSCACCBHI, 7;否。ACCB为负? GOTOC_norm2C_norm1BTFSCACCBHI, 6;为正。规格化完毕? RETURN ;ACCBHI.6=1, 规格化结束CALLSHFTSL;否。ACCB左移DECFEXPB ;EXPB减1GOTOC_norm1 ;重新判断规格化完毕否? C_norm2BTFSSACCBHI, 6;ACCB为负。规格化完毕否? RETURN ;ACCBHI.6=0, 规格化结束BCFSTATUS, CCALLSHFTSL ;否, ACCB左移BSFACCBHI, 7 ;加符号DECFEXPB ;EXPB减1GOTOC_norm2 ;重新判断规格化完毕否? SHFTSLBCFSTATUS, C;ACCB左移子程序RLFACCCLORLFACCCHIRLFACCBLORLFACCBHIRETURN( 6) 浮点数除法程序LISTp=16f877INCLUDEp16f877.incACCALOEQU20;存放除数的尾数ACCAHIEQU21EXPAEQU22;存放除数的阶码ACCBLOEQU23 ;存放被除数的尾数和商的尾数ACCBHIEQU24EXPBEQU25 ;存放被除数和商的阶码ACCCLOEQU26 ;存放余数ACCCHIEQU27ACCDLOEQU28;临时寄存器ACCDHIEQU29 ;临时寄存器TEMPEQU2A ;临时寄存器TEMP1EQU30