51单片机汇编语言怎样把数据表放在数据存储器中？

ID:641358 · 发表于 2024-12-31 09:02

在c51中可以用 char code table[5]={xx,xx,xx,xx,xx}的数组把数据表存放在程序存储器中，是不可修改的。如果不用code，则table是存放在数据存储器中的，是可修改的。在汇编语言中用伪指令DB来存放数据表，但这个数据表是存放在程序存储器中的，不可修改。现在的问题是，在使用汇编语言编程时，怎样将一串数据存放在数据存储器中，可以修改它，也可以用MOV A,@R0的办法来查表，而不必用MOVC 指令来取数。

ID:73992 · 发表于 2025-1-1 20:16

程序运行的时候，依次将程序存储器中的数据表读写到指定内存。然后从内存引用

ID:155507 · 发表于 2025-1-1 22:58

你可以用伪指令放进不同的段在储存器中的空间分配。

?DT?myvar  SEGMENT DATA       ; define a SEGMENT of class DATA
         RSEG ?DT?myvar
VALUE:    DS    1          ; reserve 1 BYTE in DATA space

IO_PORT2 DATA 0A0H       ; special function register
VALUE2    DATA 20H       ; absolute memory location

?BI?mybits SEGMENT BIT       ; define a SEGMENT of class BIT
         RSEG ?BI?mybits
FLAG:    DBIT 1          ; reserve 1 Bit in BIT space
P1       DATA 90H       ; 8051 SFR PORT1
GREEN_LED  BIT    P1.2       ; GREEN LED on I/O PORT P1.2

?ID?myvars SEGMENT IDATA       ; define a SEGMENT of class IDATA
         RSEG ?EB?mybits
BUFFER: DS    100       ; reserve 100 Bytes

?XD?my_seg SEGMENT XDATA             ; define a SEGMENT of class XDATA
         RSEG ?ED?my_seg
XBUFFER: DS    100                ; reserve 100 Bytes

?CO?my_seg SEGMENT CODE             ; define a SEGMENT of class CODE
         RSEG ?CO?my_seg
TABLE:    DB    1,2,4,8,0x10       ; a table with constant values

?PR?myprog SEGMENT CODE       ; define a segment for program code
         RSEG ?PR?myprog
         MOV    A,IO_PORT2 ; direct memory access to DATA
         ADD    A,VALUE
         MOV    VALUE2,A
         MOV    R1,#VALUE ; load address of VALUE to R1
         ADD    A,@R1       ; indirect memory access to VALUE

ID:624769 · 发表于 2025-1-2 00:34

不建议你学汇编，因为汇编需要对单片机工作原理有一定的理解，而你对单片机的工作原理好像一无所知。

单片机上电后，DATA (数据存储器) 中是随机值，并不会保留以前的任何数据，因此，如果你需要把数组（一串数据）放在 DATA (数据存储器)中，首先，你需要把这些数据利用 DB 放在 CODE(程序存储器) 中，然后，再在程序中，通过 MOVC A,@A+DPTR 以及 MOV @R1,A 把数组存到 DATA (数据存储器)中。

真要从基础开始认真学汇编的话，是不会问这个问题的……

ID:235200 · 发表于 2025-1-2 09:09

要实现你的问题，只能采用数组形式存放，而且只能存放在内存中

ID:341045 · 发表于 2025-1-2 10:22

直接往里塞就行了呀。如MOV 30H,#1; MOV 31H,#2; MOV 32H,#3; MOV 33H,A

ID:641358 · 发表于 2025-1-3 15:17

lzts88 发表于 2025-1-2 10:22
直接往里塞就行了呀。如MOV 30H,#1; MOV 31H,#2; MOV 32H,#3; MOV 33H,A

这种方法我也想过，就是显得有点笨拙，但这应该是最基本的。

ID:641358 · 发表于 2025-1-3 16:49

csmyldl 发表于 2025-1-2 09:09
要实现你的问题，只能采用数组形式存放，而且只能存放在内存中

关键是汇编语言没有数组的说法。

ID:384109 · 发表于 2025-1-3 21:10

只能用MOV A,@R0的方式读写，存放的时候注意存放在一个连续区域就行了，数组也只不过是存在连续区域的数据而已

ID:641358 · 发表于 2025-1-5 19:21

人中狼发表于 2025-1-3 21:10
只能用MOV A,@R0的方式读写，存放的时候注意存放在一个连续区域就行了，数组也只不过是存在连续区域的数据 ...

这还是一个数一个数的存，而不能像C语言一样一次性存储多个数据。

ID:155507 · 发表于 2025-1-5 22:51

tzqi 发表于 2025-1-5 19:21
这还是一个数一个数的存，而不能像C语言一样一次性存储多个数据。

因为在C语言，你在做数组到时候他就会带入，这一个程序。

;------------------------------------------------------------------------------
; This file is part of the CX51 Compiler package
;
; *** <<< Use Configuration Wizard in Context Menu >>> ***
;------------------------------------------------------------------------------
; INIT_MX.A51: This code is executed, if the application program contains
; initialized variables at file level.
;
; If you are using uVision2, just add the file as last file to your project.
; *** IMPORTANT NOTE ***: this file needs to be the last file of the linker
; input list. If you are using uVision2 this file should be therefore the
; last file in your project tree.
;
;
; To translate this file use Ax51 with the following invocation:
;
; AX51 INIT_MX.A51
;
; To link the modified INIT_MX.OBJ file to your application use the following
; linker invocation:
;
; LX51 your object file list, INIT.OBJ controls
;
;------------------------------------------------------------------------------
;
; User-defined Watch-Dog Refresh.
;
; If the C application contains many initialized variables uses a watchdog
; it might be possible that the user has to include a watchdog refresh into
; the initialization process. The watchdog refresh routine can be included
; in the following MACRO and can alter all CPU registers except
; DPTR.
;
WATCHDOG MACRO
; Include any Watchdog refresh code here
ENDM
;
;------------------------------------------------------------------------------
;
;<h> Far Memory Support
;
; If the C application contains variables in the far memory space that are
; initialized, you need to set the following define to 1.
;
; --- Set XBANK = 1 when far variables should be initialized
; <q> XBANK: Initialize variables in far memory
; <i>If the C application contains variables in the far memory space that are
; <i>initialized, you need to check this box.
$SET (XBANK = 1)
;
;</h>
;------------------------------------------------------------------------------
; Standard SFR Symbols
ACC DATA 0E0H
DPL DATA 82H
DPH DATA 83H
NAME ?C_INIT
?C_C51STARTUP SEGMENT CODE
?C_INITSEG SEGMENT CODE ; Segment zur Initialisierung
INIT_IorP MACRO
IorPData: ; If CY=1 PData Values
CLR A
MOVC A,@A+DPTR
INC DPTR
MOV R0,A ; Start Address
IorPLoop: CLR A
MOVC A,@A+DPTR
INC DPTR
JC PData
MOV @R0,A
SJMP Common
PData: MOVX @R0,A
Common: INC R0
DJNZ R7,IorPLoop
JMP Loop
ENDM
EXTRN CODE (MAIN)
PUBLIC ?C_START
RSEG ?C_C51STARTUP
INITEND: EJMP MAIN
$IF (XBANK = 0)
INIT_IorP
$ENDIF
Bits: CLR A
MOVC A,@A+DPTR
INC DPTR
MOV R0,A
ANL A,#007H
ADD A,#Table-LoadTab
XCH A,R0
CLR C
RLC A ; Bit Condition to Carry
SWAP A
ANL A,#00FH
ORL A,#20H ; Bit Address
XCH A,R0 ; convert to Byte Addressen
MOVC A,@A+PC
LoadTab: JC Setzen
CPL A
ANL A,@R0
SJMP BitReady
Setzen: ORL A,@R0
BitReady: MOV @R0,A
DJNZ R7,Bits
SJMP Loop
Table: DB 00000001B
DB 00000010B
DB 00000100B
DB 00001000B
DB 00010000B
DB 00100000B
DB 01000000B
DB 10000000B
?C_START:
MOV DPTR,#?C_INITSEG
Loop:
WATCHDOG
CLR A
MOV R6,#1
MOVC A,@A+DPTR
JZ INITEND
INC DPTR
MOV R7,A
ANL A,#3FH
JNB ACC.5,NOBIG
ANL A,#01FH
MOV R6,A
CLR A
MOVC A,@A+DPTR
INC DPTR
JZ NOBIG
INC R6
NOBIG: XCH A,R7
; ---- Init for far Variables
$IF (XBANK = 1)
ANL A,#0E0H
CJNE A,#0E0H,NOHDATA
;
HPTRINIT: CLR A
MOVC A,@A+DPTR
MOV R3,A
INC DPTR
CLR A
MOVC A,@A+DPTR
MOV R2,A
INC DPTR
CLR A
MOVC A,@A+DPTR
MOV R1,A
INC DPTR
HLOOP: CLR A
MOVC A,@A+DPTR
EMOV @PR0,A
INC DPTR
INC R1
MOV A,R1
JNZ HINC
INC R2
HINC: DJNZ R7,HLOOP
DJNZ R6,HLOOP
SJMP Loop
NOHDATA:
$ENDIF
ANL A,#0C0H ; Typ is in Bit 6 and Bit 7
ADD A,ACC
JZ IorPData
JC Bits
XdataMem: CLR A
MOVC A,@A+DPTR
INC DPTR
MOV R2,A ; High
CLR A
MOVC A,@A+DPTR
INC DPTR
MOV R0,A ; LOW
XLoop: CLR A
MOVC A,@A+DPTR
INC DPTR
XCH A,R0
XCH A,DPL
XCH A,R0
XCH A,R2
XCH A,DPH
XCH A,R2
MOVX @DPTR,A
INC DPTR
XCH A,R0
XCH A,DPL
XCH A,R0
XCH A,R2
XCH A,DPH
XCH A,R2
DJNZ R7,XLoop
DJNZ R6,XLoop
SJMP Loop
$IF (XBANK = 1)
INIT_IorP
$ENDIF
RSEG ?C_INITSEG
DB 0
;-------------------------------------------------------------------------
; STRUCTURE OF THE INITIALIZATION INFORMATION
; -------------------------------------------
; This section describes the initialization data generated by C51 for
; explicit variable initializations (in segment ?C_INITSEC).
;
; Explicit variable initilizations at C source level are stored by C51 in
; the segment ?C_INITSEC. All partial segments are combined at linker level
; to one segment. The segment end value DB 0 is taken from this library module
; INIT.A51.
;
; Structure of the ?C_INITSEC information:
; Info (see below) [BYTE] ----+ repeated
; additional info [BYTES depend on Info] ----+ repeated
; 0x00 [BYTE] end of list mark
;
; Info has the following format:
;
; Bit 7 6 5 4 3 2 1 0
; Info T T B L L L L L T=Type B=BIGBIT L=LENGTH
;
; If BIGBIT is set, another LENGTH BYTE FOLLOWS. The LENGTH
; info of the first byte is then the HIGH part.
;
; Typ is one of the following:
; 0 := IDATA init values; the following bytes follow:
; - 1 byte address
; - init data bytes according LENGTH specification
;
; 1 := XDATA init values; the following bytes follow:
; - 2 byte address (high byte first)
; - init data bytes according LENGTH specification
;
; 2 := PDATA init values; the following bytes follow:
; - 1 byte address
; - init data bytes according LENGTH specification
;
; 3, BIGBIT=0 := BIT init values; the followign bytes follow:
; - 1 byte for each bit according LENGTH specification
; this byte has the following format:
;
; Bit 7 6 5 4 3 2 1 0
; I B B B B B B B I := state of the bit
; B := bit address
;
; 3, BIGBIT=1 := HDATA init values; the following bytes follow:
; - another LENGTH byte (since BIGBIT is always 1)
; - 3 byte address (MSB first)
; - data bytes according LENGTH specification
;
;----------------------------------------------------------------------
END

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