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DSP ccs2 C5000编译SUBC指令实现除法
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通过编程求解y=(ax^2-bx+c)/(dx+e),将商和余数分别放在数
据存储器1000H和1001H单元。
(1)已知a=8,b=6,c=10,d=7,e=9,x=5,求y。
(2)已知a=0.9,b=0.1,c=0.5,d=0.4,e=0.2,x=0.8,求y。
.title "division.asm"
.mmregs
Y .usect "Y",10H ;若程序中要使用堆栈,必须先进行设置
X .usect "X",1
.data ; 使用伪指令.sect,.text或.data改变段
table: .word 8,6,10,7,9;分别将a,b,c,d,e放入堆栈
tal: .word 5;独立开辟空间放X的值
.def start
start: STM #Y,AR2
RPT #4
MVPD table,*AR2+ ;先开辟一个较大的堆栈区,用已知数充填
STM #X,AR3
MVPD tal,*AR3 ; 从程序存储器到数据存储器
LD #0,A
LD #0,B;累加器清0
STM #Y,AR3;将数据段的首地址给ARx
STM #X,AR2
SQURA *AR2,A ;A=(*AR2)^2
STL A,*AR4 ;将累加器的低字节赋值给AR4指向的空间
MAC *AR4,*AR3+,B ;B=aX^2计算后AR3指向下一个地址
STL B,*(0201H)
LD #0,A ;累加器初始化
MAC *AR2,*AR3+,A ;A = A+bX
STL A,*AR4
SUB *AR4,B ;B=B-*AR4 => B=aX^2-bX
ADD *AR3+,B ;B=aX^2-bX+c
STL B,*(0201H)
LD #0,A
MAC *AR2,*AR3+,A
ADD *AR3,A;A=dX+e
STM #0203h,AR4
STM #0204h,AR5
STL A,*AR4
STL B,*AR5 ;验证答案
RPT #15
SUBC *AR4,B ;除法
STL B,*(1000H) ;商
STH B,*(1001H) ;余
end: B end
.end
.title "vectors.asm"
.ref start
.sect ".vectors"
B start
.end
division.obj
vectors.obj
-o division.out
-m division.map
-estart
MEMORY
{
PAGE 0:
EPROM: org=0e000h len = 0100h
VECT: org=0ff80h len = 0004h
PAGE 1:
SPRAM: org=0060h len = 0020h
DARAM1: org=0100h len = 0010h
DARAM2: org=0080h len = 0002h
}
SECTIONS
{
.text :>EPROM PAGE 0
.data :>EPROM PAGE 0
X :>DARAM1 PAGE 1
Y :>DARAM2 PAGE 1
.vectors:>VECT PAGE 0
}
;cmd脚本文件,定义空间位置
.title "division.asm"
.mmregs ;将寄存器符号设置为全局可用
.bss a,6
.bss b,1
.data
table1: .word 8*32768/10,9*32768/10,1*32768/10,5*32768/10,4*32768/10,2*32768/10
table2: .word 8*32768/10
.def start ;.def表示某符号在本文件定义,可为其他文件引用
.text
start: SSBX FRCT
STM #a,AR2
RPT #6
MVPD table1,*AR2+
STM #b,AR3
MVPD table2,*AR3
LD #0,A
LD #0,B
STM #a,AR2
STM #b,AR3
MPY *AR3,*AR2+,A ;乘法 等同SQURA *AR3,A 得出值 假如为005F7A**** ;即00 0101 1111 0111 1010*****=2^(-1)+2^(-3)+……
如果不是特别要求可以省略低字节数据
STH A,*AR4
STH A,*(0200H) ; A=X^2的值存储在0200H
MAC *AR4,*AR2+,B
STH B,*(0201H) ;B=aX^2将值存储在0201H
LD #0,A
MAC *AR3,*AR2+,A
STH A,*AR4
SUB *AR4,16,B
ADD *AR2+,16,B
STH B,*(0202H) ;B=aX^2-bX+c的值存储在0202H
LD #0,A
MAC *AR3,*AR2+,A
ADD *AR2,16,A ;A=dX+e
STM #0203H,AR4
STH A,*AR4 ;*AR4=dX+e
;A=dX+e的值存储在0203H
STM #0204h,AR5
STH B,*AR5 ;B=aX^2-bX+c
LD #0,B
LD *AR5,B
RPT #15
SUBC *AR4,B
;XC 1,BLT
;NEG A
STL B,*(1000H)
STH B,*(1001H)
end: B end
.end
.title "vectors.asm"
.ref start
.sect ".vectors"
B start
.end
division.obj
vectors.obj
-o division.out
-m division.map
-estart
MEMORY
{
PAGE 0:
EPROM: org=0e000h len = 0100h
VECT: org=0ff80h len = 0004h
PAGE 1:
SPRAM: org=0060h len = 0020h
DARAM1: org=0100h len = 0010h
DARAM2: org=0080h len = 0002h
}
SECTIONS
{
.text :>EPROM PAGE 0
.data :>EPROM PAGE 0
.bss :>SPRAM PAGE 1
.vectors:>VECT PAGE 0
}
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