单片机4-8章.docx

Chapter 4 3. What are the pseudo instructions commonly used in the MCS-51 assembly language? What effect does each directive have?ORG addr : set starting address of the codeORG pseudo instructions always appear at the beginning of each source or data blocks can make the program, subprograms and data stored in any location fast memory. If you hold ORG instruction in the source program, the assembler 0000H unit will start making the target program. ORG control address is defined by small to large, and can not overlap.EQU : define equivalentThe operation of the address or number assigned label field data, it is also known as the equivalent instruction.DB : define byte data in code memoryThe value is stored in the table entry or entries in a row starting from the label in cellDW : define word data in code memoryEND : signal end of source fileEND command tells the assembler stop the assembler . After the END, all of the assembly languagesdo not process. Without this directive, the assembler will usually give Warning indicates.6. Provided data area from 1000H to 10FFH in external RAM, transfer the data to the area starting at 2500H in external RAM. Please write the program. START: MOV R0，#00HMOV DPTR,#1000HLOOP:MOVX A,@DPTRMOV DPH,#25HMOVX @DPTR,AMOV DPH,#10HINC DPTR INC R0DJNZ R0，LOOPSJMP $11. The crystal oscillator frequency of system is 12MHz. Write the delay subroutine with delay time of 50ms. DL50MS：MOV R4, #100DELAY1：MOV R3 , #250DELAY2：DJNZ R3, DELAY2DJNZ R4, DELAY1RET12. Analyze the role of each instruction in the following programs and show the result of corresponding register and memory unit after running.MOV A, #34H；(A)=34H MOV B, #0ABH；(B)=0ABH MOV 34H, #78H；(34H)=78H XCH A, R0；change(A),(R0)XCH A, @R0；change(A),((R0))XCH A, B；change(A),(B)SJMP $；pauseChapter 5 2. How many operation modes does the timer/counter in 8051 single chip microcomputer have ? What features do they have respectively ? 4 ,MODE0，1，2，3，4Mode0/1：In Mode 0 t