【发布时间】：2018-08-06 14:40:58
【问题描述】：
所以我在指定我应该在我的排序函数中放置交换语句的位置时遇到了麻烦。它可以在这里和那里工作，但也许我的 cmp.b/mov.b 在错误的内存地址或我的行中？我使用的是 TI MSP430，它是一个 16 位微控制器，所以它没有一些更高层设备相同的功能，所以代码必须有点简单。
;---------------------------------------------------------------------------
; MSP430 Assembler Code Template for use with TI Code Composer Studio
;
;
;---------------------------------------------------------------------------
.cdecls C,LIST,"msp430.h" ; Include device header file
;---------------------------------------------------------------------------
.def RESET ; Export program entry-point to
; make it known to linker.
;---------------------------------------------------------------------------
.text ; Assemble into program memory.
.retain ; Override ELF conditional linking
; and retain current section.
.retainrefs ; And retain any sections that have
; references to current section.
;---------------------------------------------------------------------------
ARY1 .set 0x0200 ;Memory allocation ARY1
ARY1S .set 0x0210 ;Memory allocation ARYS
ARY2 .set 0x0220 ;Memory allocation ARY2
ARY2S .set 0x0230 ;Memory allocation AR2S
RESET mov.w #__STACK_END,SP ; Initialize stackpointer
StopWDT mov.w #WDTPW|WDTHOLD,&WDTCTL ; Stop watchdog timer
;---------------------------------------------------------------------------
; Main loop here
;---------------------------------------------------------------------------
;Memory allocation of arrays must be done prior to the RESET & StopWDT
clr R4 ;Clear Register
clr R5 ;Clear Register
clr R6 ;Clear Register
SORT1 mov.w #ARY1, R4 ;Initialize R4 to point to ARY1 in the
memory
mov.w #ARY1S, R6 ;Initialize R6 to point to ARY1S in the
memory where the sorted ARY1 will be
stored
call #ArraySetup1 ;Create elements are store them in ARY1
call #COPY ;Copy the elements from the ARY1 space
to ARY1S space
call #SORT ;Calling Subroutine Sort with parameter
passing in R4 abd R6
SORT2 mov.w #ARY2, R4 ;Initialize R4 to point to ARY2 in the
memory
mov.w #ARY2S, R6 ;Initialize R6 to point to ARY2S in the
memory where the sorted ARY2 will be
stored
call #ArraySetup2 ;Create elements are store them in ARY2
call #COPY ;Copy the elements from the ARY2 space to
ARY1S space
call #SORT ;Calling Subroutine Sort with parameter
passing in R4 abd R6
Mainloop jmp Mainloop ;loop in place for ever
;Array element initialization Subroutine
ArraySetup1 mov.b #10, 0(R4) ;Define the number of elements in the
array
mov.b #17, 1(R4) ;store an element
mov.b #75, 2(R4) ;store an element
mov.b #-67, 3(R4) ;store an element
mov.b #23, 4(R4) ;store an element
mov.b #36, 5(R4) ;store an element
mov.b #-7, 6(R4) ;store an element
mov.b #44, 7(R4) ;store an element
mov.b #8, 8(R4) ;store an element
mov.b #-74, 9(R4) ;store an element
mov.b #18, 10(R4) ;store an element
;store the rest of the 10 elements
ret
;Array element initialization Subroutine
ArraySetup2 mov.b #10, 0(R4) ;Define the number of elements in
the array
mov.b #54, 1(R4) ;store an element
mov.b #-4, 2(R4) ;store an element
mov.b #-23, 3(R4) ;store an element
mov.b #-19, 4(R4) ;store an element
mov.b #-72, 5(R4) ;store an element
mov.b #-7, 6(R4) ;store an element
mov.b #36, 7(R4) ;store an element
mov.b #62, 8(R4) ;store an element
mov.b #0, 9(R4) ;store an element
mov.b #39, 10(R4) ;store an element
;store the rest of the 10 elements
ret
;Copy original Array to allocated Array-Sorted space
COPY mov.b 0(R4), R10 ;save n (number of elements) in R10
inc.b R10 ;increment by 1 to account for the byte n to
be copied as well
mov.w R4, R5 ;copy R4 to R5 so we keep R4 unchanged for
later use
mov.w R6, R7 ;copy R6 to R7 so we keep R6 unchanged for
later use
LP mov.b @R5+, 0(R7) ;copy elements using R5/R7 as pointers
inc.w R7
dec R10
jnz LP
ret
;Sort the copy of Array saved in the allocated Array-Sorted space, while
keeping original Array unchanged
;replace the following two lines with your actual sorting algorithm.
;Sort the copy of Array saved in the allocated Array-Sorted sapce, while
keeping original Array unchanged
SORT
clr R7
clr R8
clr R9
clr R10
clr R11
clr R12
clr R13
clr R14
clr R15
mov.b R5, R11 ;counter
dec R11
mov.b @R4+, R7
mov.b @R4, R8
cmp.b R7,R8
* jz noswap
* jge No_Swap
mov.b R7, R9
mov.b R8, R7
mov.b R9, R8
inc R10
mov.b r8, 0(r4)
mov.b r7, -1(r4)
dec R11
tst R11
* jnz Swap
cmp.w #0, R10 ; swap counter
* jnz Swap
ret
;To bubble sort, you need to scan the array n-1 times,
;In every scan, you compare from top down each two consecutive elements, and
you swap them if they are not in ascending order.
;Notice that in the first scan you get the largest element (no matter where
it is in the array) pushed all the way to the bottom.
;So your next scan should be n-1 iterations, and then n-2 and so on.
;So every time you come back to the top of the array for a new scan, your n
(the number of comparisons) must be decremented by 1.
;In the last scan, you need only one comparison.
;Hints:
;Your sorting algorithm starts with R6 as a pointer to the array
;you need to save n (number of elements) in R8, then decrement it by 1 (n-1)
to become the number of comparisons.
;Copy R6 to R7 so you keep R6 unchanged as it points to the top of the array
for every new scan.
;Copy n-1 to R9 and use R9 as a loop counter, while keeping the current n-1
value in R8 for the next scan.
;In the scan loop get an element and auto increment pointer R7, then get
next element without changing R7.
;Compare the two elements, if not in ascending order, swap them.
;Repeat the scan from the top as pointed to by (R6), and every time
decrement the number of comparisons (R8).
;--------------------------------------------------------------------------
; Stack Pointer definition
;--------------------------------------------------------------------------
.global __STACK_END
.sect .stack
;--------------------------------------------------------------------------
; Interrupt Vectors
;--------------------------------------------------------------------------
.sect ".reset" ; MSP430 RESET Vector
.short RESET
【问题讨论】：
标签： arrays assembly bubble-sort msp430