LABORATORY MANUAL MICROPROCESSORS AND MICROCONTROLLERS. S.E (I.T) ( S e m. IV)

Transcription

1 LABORATORY MANUAL MICROPROCESSORS AND MICROCONTROLLERS S.E (I.T) ( S e m. IV) 1

2 I n d e x Serial No. T i tl e P a g e N o. 1 8 bit addition with carry bit addition with carry bit multiplication bit multiplication 7 5 To implement block transfer 8 6 To clear 10 bytes string 2 loop instructions /8 bit subtraction 10 7 To count no of one s in a single byte number 11 8 To count no of even and odd number in 10 given number 12 9 Arranging numbers in ascending order Average of 10 numbers To check whether a given string is Palindrome Block transfer using Toggle bits for port Serial data transfer to transmit character A To generate square wave of 50 % duty cycle using To expand I/O port of 8051 using

3 L a b S e s s i o n 1 T i t l e : O b j e c t i v e : R e f e r e n c e s : T h e o r y : To add two 8 bit numbers. Program involves storing the t w o 8-bit nos in memory locations a n d adding them taking i n t o c o n s i d e r a t i o n t h e c a r r y g e n e r a t e d. T h e o b j e c t i v e o f t h i s p r o g r a m i s t o g i v e a n o v e r v i e w o f a r i t h m e t i c i n s t r u c t i o n s o f f o r 8 -b i t o p e r a n d s /8088 Family, Architecture, Programming and Design - Y u -Cheng Lui, lenn Gibsons /8088 Interfacing, Programming and Design - John Uffenback 1. Knowledge of TASM directives. 2. Knowledge of Arithmetic Instructions of 8086 for 8-b i t operands. The addressing modes used in program are: 1) Direct addressing mode: in this mode address of operand is directly Specified instruction that address is offset address of the segment being indicated by instruction e.g. MOV CL, [4521H] assume DS = 5000 H therefore PA = =54321 therefore CL = [54321 H] 2) Register Addressing Mode: In this mode operand are specified using registers. Instructions are shorter but operations cannot be identified looking at instruction. e.g. MOV CL,DL 3) Based Indexed Addressing Mode: The operand address is calculated as base register plus index register. e.g. MOV DX, [BX + SI] moves word from address pointed by BX + SI in data segment to DS. EA = DS x 10H + BX + SI 4) Base index plus displacement In this mode address of operand is calculated base register plus index register plus displacement. e.g. MOV CX, [BX+DI+DS] This moves a word from address pointed by BX + DI + DS in data segment to CX. 1. Initialize the data segme n t. 2. Store t w o 8 -bit numbers in memory locations. 3. M o v e t h e 1 s t n u m b e r i n a n y o n e o f t h e g e n e r a l p u r p o s e r e g i s t e r. 4. M o v e t h e 2 n d number in any other general purpose register. 5. Add the 2 numbers. 3

4 6. S t o r e t h e r e s u l t i n m e m o r y l o c a t i o n. 7. Check for carry flag. If carry flag is set then store '1' as MSB o f r e s u l t. 8. Stop P o s t L a b A s s i gn m e n t s : 1. Explain arithmetic instructions of Explain TASM directives. 3. Explain the instances when the carry flag is set. 4

5 L a b S e s s i o n 2 T i t l e : Objective: T h e o r y : TO ADD TWO 16 BIT NUMBERS P r o g r a m i n v o l v e s s t o r i n g t h e t w o 1 6 b i t n u m b e r s i n m e m o r y l o c a t i o n s a n d a d d i n g t h e m taking into consideration the carry generated. The objective of this program is to give an o v e r v i e w o f a r i t h m e t i c i n s t r u c t i o n s o f f o r 1 6 b i t o p e r a t i o n. 1. Instructions of microprocessor Addressing mode of microprocess o r Flag register of microprocessor Knowledge of tasm directories.. Base index displacement addressing mode is used for 16 bit addition. H e r e t h e effective address is obtained by adding displacement value with base register and index register.. 1. Initialize the data segment. 2. Store two 16 bit numbers in memory locations. 3. M o v e t h e 1 s t n u m b e r i n a n y o n e o f t h e g e n e r a l p u r p o s e r e g i s t e r. 4. M o v e t h e 2 n d number in any other general purpose register. 5. Add the 2 numbers. 6. S t o r e t h e r e s u l t i n m e m o r y l o c a t i o n. 7. Check for carry flag. If carry flag is set then store '1' as MSB of result. 8. Stop O b s e r vations: 1. Fill the table of registers with it s contents after execution of specific i n s t r u c t i o n s. 2. Fill the table of Memory with the address and data of the numbers on which operation is performed and final result\s obtained. Post Lab Assignments: 1. List of condition of the flag in the status register after ADD instructions has been executed. 2. Some 8086 mnemonics which is used for addition and storing a DATA 5

6 L a b S e s s i o n 3 Title : Objective: Theory: Observations: TO PERFORM 8 BIT MULTIPLICATION. P r o g r a m i n v o l v e s s t o r i n g t h e t w o 8 b i t n u m b e r s i n m e m o r y l o c a t i o n s a n d p e r f o r m i n g m u l t i p l i c a t i o n o p e r a t i o n. 1. Instructions of microprocessor Addressing mode of microprocessor Flag register of microprocessor Knowledge of tasm directories. M U L i n s t r u c t i o n T h i s i n s t r u c t i o n multiplies byte/word present in source with AL/Ax. After 8 bit multiplication AH stores the higher byte of result. After 16 bit multiplication DX stores higher word of result e.g. MUL BL T h i s i n s t r u c t i o n m u l t i p l i e s d a t a i n B L r e g i s t e r w i t h d a t a i n A L r e g i s t e r. R e s u l t i s stored in AX register where AH store higher byte of result. 1. Initialize the data segment. 2. I n i t i a l i z e g e n e r a l p u r p o s e r e g i s t e r. 3. Mo v e t h e c o n t e n t o f D S t o A L r e g i s t e r. 4. Increment general purpose register by M o v e c o n t e n t o f D S t o a n y o t h e r 8 b i t r e g i s t e r. 6. Perform multiplication operation using MUL instruction 7. Stop 1. Fill the table of registers with i t s con t e n t s a f t e r e x e c u t i o n o f s p e c i f i c i n s t r u c t i o n s. 2. Fill the table of Memory with the address and data of the numbers on which o p e r a t i o n i s performed and final result\s obtained. Post Lab Assignments: 1.List of condition of the flag in the status register after MUL instructions has been executed. 2. Some 8086 mnemonics which is used for multiplication and storing a DATA 6

7 L a b S e s s i o n 4 Title : Objective: T h e o r y : O b s e r v a t i o n s : TO MULTIPLY TWO 16 BIT NUMBERS P r o g r a m i n v o l v e s s t o r i n g t h e t w o 1 6 b i t n u m b e r s i n m e m o r y l o c a t i o n s a n d m u l t i p l y i n g t h e m t h e o b j e c t i v e o f t h i s p r o g r a m i s t o g i v e a n o v e r v i e w o f a ri t h me ti c i ns tr u ct i on s o f f o r 1 6 b i t o p e r a t i o n. 1. Instructions of microprocessor Addressing mode of microprocessor Flag register of microprocessor Knowledge of tas m d i r e c t o r i e s. This can be perform by using MUL instruction. Out of two 16 bit operands, one 16 bit operand is stored in AX register and the other operand is stored in a general purpose register or a memory location which mentioned in i n s t r u c t i o n. e.g. MUL BX M u l t i p l i e s c o n t e n t o f A X a n d B X r e g i s t e r. T h e r e s u l t i s 3 2 b i t d a t a. T h e h i g h e r 1 6 b i t o f r e s u l t i s s t o r e d i n D X r e g i s t e r a n d t h e l o w e r 1 6 b i t s o f r e s u l t i s s t o r e d i n A X register. MUL Word PTR [1150]: Multiplies content of memory location pointed by 1150 & 1151 & AX r e g i s t e r & s t o r e d t h e h i g h e r 1 6 b i t i n DX register & lower 16 bit in Ax r e g i s t e r. 1. Initialize the data segment. 2. Store two16 bit numbers in memory locations. 3. M o v e t h e 1 s t n u m b e r i n a n y o n e o f t h e g e n e r a l p u r p o s e r e g i s t e r. 4. M o v e t h e 2 n d number in any other general pu r p o s e r e g i s t e r. 5. Multiply the 2 numbers. 6. S t o r e t h e r e s u l t i n m e m o r y l o c a t i o n. 7. Stop. 1. Fill the table of registers with i t s c o n t e n t s a f t e r e x e c u t i o n o f s p e c i f i c i n s t r u c t i o n s. 2. Fill the table of Memory with the address and data of the numbers on Wh i c h o p e r a t i o n i s p e r f o r m e d a n d f i n a l r e s u l t s obtained. Post Lab Assignments: 1. List of condition of the flag in the status register after MUL instructions has been executed. 2. Some 8086 mnemonics which is used for multiplication and storing a DATA 7

8 L a b S e s s i o n 5 T i t l e : O b j e c t i v e : R e f e r e n c e s : T h e o r y : TO IMPLEMENT BLOCK TRANSFER. Program involves transferring source string from a particular l o c a t i o n i n s o u r c e s e g m e n t ( D a t a S e g m e n t ) t o t h e d e s i r e d l o c a t i o n i n d e s t i n a t i o n s e g m e n t ( E x t r a S e g m e n t ). T h e o b j e c t i v e o f t h i s p r o g r a m i s t o g i v e a n o v e r v i e w o f t h e S t r i n g i n s t r u c t i o n s o f /8088 Family, Architecture, Programming and Design -Y u -Cheng Lui,Glenn Gibsons /8088 Interfacing, Programming and Design - John Uffenback 1. Knowledge of TASM directives. 2. Knowledge of String Instructions of A string is a series of bytes stored sequentially in the memory string instruction operate on such strings. The sequence element is taken from the data segment using the SI r e g i s t e r t h e destination element is in the extra segment pointed by DI register. S I / D I a r e incremented/ decremented after each operation depending upon the destination flag OF in the flag register. MOVS: MOVSB/MOVSW (move string) It is used to transfer a word/byte from data segment to extra segment the offset of the source in data segment is in SI the offset of the destination is in ES in DI. SI & DI i s incremented / D e c r e m e n t e d a f t e r t h e t r a n s f e r d e p e n d i n g u p o n t h e d i r e c t i o n f l a g. REP (Repeat) : This is an instruction prefix in which can be used in string instruction. It causes the i n s t r u c t i o n t o b e repeated (X n u m b e r o f t i m e ) e.g. MOV CX,0023H CLD R E P M O V SB. 1. Initialize the data segment. 2. Store the source string in consecutive memory location. 3. Initialize the extra segment. 4. Allocate consecutive memory locations for transfer. 5. Load the effective address of source string in SI register. 6. Load the effective address of destination string in DI register. 7. Initialize the Direction flag for Auto increment or Auto decrement. 8. Store number of bytes to be transferred in any of the general purpose registers. 9. Transfer the source string using appropriate string instructions ( M O V S B / MOVSW) 8

9 10. Decrement count. 11. Check if count = 0.If yes then stop else repeat steps Stop P o s t L a b A s s i gn m e n t s : 1. Explain string instructions. 2. Explain the purpose of direction flag. 3. Explain the REP prefix. 4. Explain the difference between CMP and CMPSB 9

10 L a b S e s s i o n 6 Title: O b j e c t i v e : R e f e r e n c e s : TO CLEARING DATA IN MEMORY LOCATION. Program involves clearing data from a particular l o c a t i o n i n s o u r c e s e g m e n t ( D a t a S e g m e n t ). The objective of this program is to give an overview of the String i n s t r u c t i o n s of /8088 Family, Architecture, Programming and Design - Y u -Cheng Lui,Glenn Gibsons /8088 Interfacing, Programming and Design - John Uffenback 1. Knowledge of TASM directives. 2. Knowledge of String Instructions of T h e o r y : The clearing of 10 bytes of data in memory location can be done using s t r i n g i n s t r u c t i o n. STOSB : this string instruction is repeated 10 times using repeat ( REP)prefix. e.g. STOSB T h i s instruction copies the content of AX register and stores it in the memory location provided by ES: D I. Thus by string zero in AL register we can clear 10 bytes of data using STOSB. The ES & DI should point to the memory location w h i c h h a s t o b e cleared. 1. Initially ES & DS such that it points to the memory location which has to be c l e a r e d f i r s t. 2. Set the counter register (CX) to Set AL register to value zero. 4. Per for m STOSB operation to clear the memory. 5. Increment DI. 6. Repeat STOSB using REP prefix, count number of time. 7. Thus 10 consecutive memory locations are cleared. 8. Stop. P o s t L a b A s s i gn m e n t s : 1. Explain string instructions. 2. E x p l a i n t h e R E P p r e f i x. 10

11 L a b S e s s i o n 7 T i t l e : O b j e c t i v e : R e f e r e n c e s : TO COUNT A NUMBER OF 1 S IN A GIVEN STRING. Program involves counting of 1 s in a given string. The objective of this program is t o g i v e an overview of the String instructions of /8088 Family, Architecture, Programming and Design - Y u -Cheng Lui,Glenn Gibsons /8088 Interfacing, Programming and Design - John Uffenback 1..Knowledge of TASM directives. 2. Knowledge of String Instructions of T h e o r y : The program involves counting the number of 1 s in a given 16 bit/ 8 bit number. T h e i n s t r u c t i o n u s e d i n t h i s p r o g r a m i s R O L. ROL dest, count Left shift the bit of destination. MSB shifted to the carry. MSB goes to LSB. Bits are used shifted count number of times. If count = 1. It is specified in instruction if count > 1 l o a d t o C L r e g i s t e r a n d C L g i v e s c o u n t i n t h e i n s t r u c t i o n. D e s t i n a t i o n : R e g i s t e r a s m e m o r y l o c a t i o n. e.g. ROL AX,1 left shift X bits once. 1. Initialize the data segment. 2. Initialize BL = 0 3. Load given number. 4. Perform ROL and Al 5. If CF = 1, increment else decrement CX and Check zero flag. 6. Repeat till zero 12. Stop P os t L a b A s s i gn m e n t s : 1. Explain Logical instruction in

12 L a b S e s s i o n 8 T i t l e : T O F I N D E V E N A N D O D D N U M B E R S I N A GI V E N S T R I N G. O b j e c t i v e : R e f e r e n c e s : Theory: Program involves counting the even and odd numbers in a given array. The objective of t h i s p r o g r a m i s t o g i v e an overview of the String instructions of /8088 Family, Architecture, Programming and Design - Y u -Cheng Lui, Glenn Gibsons /8088 Interfacing, Programming and Design - John Uffenback 1. Knowledge of TASM directives. 2. Knowledge of String Instructions of A string is a series of bytes stored sequentially in the memory string instruction Operate on such strings. The SRC element is taken from the data segment using and S1 register. The destination element is in extra segment pointed by D1 register. These registers are incremented or decremented after each operation depending upon the direction flag in flag register. CLC: - the instruction clears the carry flag. RCR: - destination, count Right shift the bits of destination. LSB is shifted into CF. CF goes to MSB. Bits Are shifted counts no of times. J C: jump to specified location. INC/DFC destination: add 1 to the specified location. If CF is set to 1.No CF is affected for DFC. JMP: Depending upon the location the control is shifted there (intra/inter seg) JNZ: jump to location if ZF = Initialize the data segment. 2. Initialize the array. 3. Load the effective address of array in any general purpose register. 4. Load total number of elements of the array in any register. 5. Test LSB of CX register. If LSB =1then no. is odd else no. is even. 6. St ore result in DX register. 7. Stop. P o s t L a b A s s i gn m e n t s : 1. E x p l a i n s hi ft & r ot at e in s t r u c t i o n s. L a b S e s s i o n 9 12

13 T i t l e : O b j e c t i v e : R e f e r e n c e s : Theory: ARRANGING NUMBER IN ASCENDING ORDER. Program involves sorting an array in ascending order using Bubble sort algorithm. The objective of this program is to give an overview of the C o m p a r e a n d J u m p i n s t r u c t i o n s. U s e o f I n d i r e c t A d d r e s s i n g m o d e f o r a r r a y a d d r e s s i n g i s e x p e c t e d /8088 Family,Architecture,Programming and Design - Y u-cheng Lui,Glenn Gibsons /8088 Interfacing,Programming and Design - John Uffenback 1. Knowledge of TASM directives. 2. Knowledge of CMP and Jump Instructions of ) compare instruction: CMP dest, source The instruction compares the source with destination. The source and destination m u s t be of same size. Comparison is done by internally subtracting source from destination. The result of this is not stored anywhere instead flag bits are affected. 2) JMP instruction: if condition is true then it is similar to then it is similar to an intra segment branch and if false then branch does not take place & next instruction is executed. T h e d e s t i n a t i o n m u s t b e i n r a n g e o f -128 to 127 from address of instruction. INC next: Short jump to next only if CF = 0 1. Initialize the data segment. 2. I n i t i a l i z e the array to be sorted. 3. Store the count of numbers in a register. 4. Store count-1 in another register. 5. Load the effective address of array in any general purpose register. 6. Load the first element of the array in a register. 7. Compare with the next element of the array. 8. Check for carry flag. 9. If carry=0 first number > second number. Swap the 2 numbers. 10. Increment to the contents of the SI register so that it points to the next element of the array. 11. Decrement (count-1) by Check if (count-1) =0. If no then repeat steps 7 to Decrement count by Check if count = 0.If no then repeat steps 6 through 15. Stop. P o s t L a b A s s i gn m e n t s : 1.Explain CMP and Jump Instructions. 2.Explain Indirect Addressing Modes. L a b S e s s i o n

14 T i t l e : O b j e c t i v e : R e f e r e n c e s : Theory: TO FIND AVERAGE OF 10 NUMBERS. Program involves averaging of a ten numbers /8088 Family,Architecture,Programming and Design - Y u-c h e n g Lui,Glenn Gibsons /8088 Interfacing,Programming and Design - John Uffenback 1. Knowledge of TASM directives. 2. Knowledge of CMP and Jump Instructions of CLC: Clears carry flag. No other flags affected. L E A : l o a d e f f e c t i v e a d d r e s s o f s o u r c e i n t o g i v e n r e g i s t e r. E.g. LEA BX, t o t a l : B X effective address of total. A D C d e st, source: Adds source to destination along previous carry & stores it in destination. Both s o u r c e & d e s t i n a t i o n h a v e t o be of same size. E.g. A D C BX, C X ; BX- BX+ CX+ CF JNZ: jump to location if ZF= 0 DEC destination: subtracts 1 from specified destination. I N C d e s t i n a t i o n : Add 1 to destination. 1. Initialize the data segment. 2. C l e a r c a r r y f l a g. 3. Store initial address of list in a register. 4. Move 0A to register AL. 5. Store count in register AL. 6. Reset AL registers (content of AX) 7. Add one number from array to contents of AL 8. Decrement count 9. I n c r e m e n t S I 10. If count 0 go to step Divide content of AX with that of BL. 12. Store answer in register. 13. Stop. P o s t L a b A s s i gn m e n t s : 1. Write different instructions used. L a b S e s s i o n

15 T i t l e : Obj e c t i v e : D i s p l a y Character from keyboard until 0 is entered. T o R e a d C h a r a c t e r f r o m K e y b o a r d a n d d i s p l a y o n s c r e e n u n t i l 0 i s p r e s s e d. 1. Knowledge of TASM directives. 2. Knowledge of DOS Interrupt. Theory: Instruction used in program are: M O V A H, 0 8 H I N T 2 1 H Read Input From Keyboard without echo and store at AL. MOV AH,02H INT 21H Display Character on screen. Character should be in DL register. 1. Initialize the data segment. 2. Read input from keyboard. 3. Compare input with ASCII value of ZERO. 4. I f r e s u l t i s 0, g o t o s t e p Move content of AL to DL, to display it on screen. 6. Display character on screen. 7. Stop 15

16 L a b S e s s i o n 1 2 T i t l e : O b j e c t i v e : Password Verification T h e o b j e c t i v e i s t o m a k e u s e o f s t r i n g i n s t r u c t i o n a n d M A C R O, t o c h e c k w h e t h e r t h e e n t e r e d p a s s w o r d b y t h e u s e r i s c o r r e c t o r n o t. 1. Knowledge of TASM directives. 2. Knowledge of DOS interrupt. 3.Knowledge of string instruction and MACRO. 1. S t o r e I n i t i a l p a s s w o r d i n t o A r r a y. 2. Write Macro for printing output message. 3. W r i t e M a c r o t o d i s p l a y *. 4. I n i t i a l i z e t h e d a t a s e g m e n t. 5. Set the counter value=no. of character present in password. 6. Load Effective address of stored password in BX. 7. Take input from the keyboard. 8. Compare input with the password string. 9. I f z e r o = 0, b o t h v a l u e a r e e q u a l. G o t o s t e p 1 0. If zero is not equal to 0.Go to step display * Macro I n c r e m e n t B X. 12. Decrement counter by Check if counter=0.if not, Repeat step 7 to Display Macro message for correct password, Go to step Display * macro and Macro message for wrong password E n d P o s t L a b A s s i gn m e n t s : 1. Explain Macro.. L a b S e s s i o n

17 T i t l e : O b j e c t i v e : Algorithm: To write a program for 3 X 3 matrix Addition T h e o b j e c t i v e i s t o m u l t i p l y 3 X 3 m a t r i x. 1. Knowledge of TASM directives. 2. Knowledge of DOS interrupt. 3.Knowledge of string instruction and MACRO 1. Initialize the data segment. 2. Initialise counter = 9 3. Initialize pointer DI to matrix Initialize pointer Bx to matrix Initialize pointer SI to result matrix Get the number from matrix Add number from matrix 1 with matrix 1 number. 8. Save the carry if any. 9. S a v e t h e r e s u l t i n r e s u l t m a t r i x Increment DI,BX,SI to point to next element. 11. D e c r e m e n t c o u n t. 12. Check if count = 0,if not goto step VI else goto step XIII 13. Display the result. 14. S t o p. L a b S e s s i o n 11 17

18 T i t l e : T O C H E C K I F T H E E X TE R N A L S TR I N G I S A P A L I N D R OM E O R N O T. O b j e c t i v e : Pre-Requisites: To search the given string is palindrome. 1. Knowledge of string instruction. 2. Knowledge of TASM directive. 3. Addressing mode of microprocessor F l a g r e g i s t e r o f m i c r o p r o c e s s o r R e f e r e n c e : /8088 Family,Architecture,Progra m m i n g a n d D e s i g n - Y u -Cheng Lui,Glenn Gibsons /8088 Interfacing,Programming and Design - John Uffenback T h e o r y : String instruction/ data transfer LEA register, Source Load effective address (offset Address) of source in given register. e.g. LEA BX, Total; BX Effective address of Total DS. STOSB/ STOSW ( Stor e string) It is used to store AL( or AX) into a m e m o r y location pointed by ES:DI DI is incremented ( decremented after transfer depending upon DF) LODSB/LODSW: Used to copy the contents of memory location pointed by DS:SI & store it in AL register SI is incremented /decremented after transfer depending upon DF. Algorithm: 1. St art 2. Define Data Segment (DS) 3. Move data segment address to register AX. 4. Move content of AX to DX 5. Move content of AX to ES. 6. Move 00 to DL. 7. Move 05 to CX 8. Load effective address of source to SI. 9. Load effective address of destination to DI. 10. Clear DF & load string in byte format. 11. Set DF. 12. Store string in by format pointed by DI. 13. Loop to the step Move 0005 to CX. 16. Clear DF. 17. Repeat if zero when comparing string in byte format. 18. Jump if not zero to Move 01h to data byte initialized. 20. Move 41H to Register AH. 21. Stop. Post Lab Assignments: 1. Explain 8086 programming in assembler. L a b S e s s i o n

19 T i t l e : O b j e c t i v e : Algorithm: To compute power of number x N using dos intrrupt. T h e o b j e c t i v e i s t o m a k e u s e o f s t r i n g i n s t r u c t i o n a n d M A C R O, t o c h e c k w h e t h e r t h e e n t e r e d p a s s w o r d b y t h e u s e r i s c o r r e c t o r n o t. 1. Knowledge of TASM directives. 2. Knowledge of DOS interrupt. 3.Knowledge of string instruction and MACRO. 1. Initialize data segment 2. Write a macro for reading a value from the keyboard 3. Write a macro for printing input message and result 4. Initialize the code segment. 5. Call the macro to input the number X & N. 6. Write a loop for calculating x N. 7. Convert the above computed value obtained in step 5 to ASCII value. 8. Call the macro to point the result. 19

20 L a b S e s s i o n 12 T i t l e : O b j e c t i v e : Pre-r e q u i s i t es : R e f e r e n c e : T h e o r y : TRANSFER A BLOCK OF MEMORY FROM ONE LOCATION TO THE OTHER IN 8051 a) To familiarize with data transfer instruction of 8051 b) General Assembly Language Programming concepts of data transfer instruction Kenneth Ayala - Penram International (II edition) Data transfer instructions are used as follows. MOV < dest - byte>, < src byte> This instruction copies the content of the source location to the destination location. The contents of source location are unchanged. It allows fifteen combinations of source and destination addressing modes. 1) MOV A, Rn : this instruction copies the contents of the register Rn to the accumulator. MOV A, R1 2 ) M O V A, D i r e c t : This instruction copies the contents of direct address given in the instruction to the accumulator. E.g. MOV a, 40H. 3) MOV Ri: This instruction will copy the contents of memory location whose address is specified in the register Ri of the selected bank of the accumulator. E.g. MOV R0. 4) MOV A, #data: this instruction will copy the immediate data to accumulator. e.g. MOV A,#31H. 5) MOV Rn, A: this instruction will copy the contents of accumulator to the register Rn of selected register bank. E.g. MOV R5, A. 6) MOV Rn, Direct: this instruction will copy contents from direct address specified in the instruction to register Rn of selected register bank. E.g. MOV R3, 30H. 7) MOV Rn, #data: this instruction will copy the immediate data to the register Rn of selected register bank. E.g. MOV R7, #20H. 8) MOV direct, A: this instruction will copy the contents of accumulator to the direct address specified in the instruction. E.g. MOV 80 H, A. 9) MOV direct, Rn: this instruction will copy the contents of register Rn of the selected register bank to the direct address specified in the instruction. E.g. MOV 30 H, R5. 10) MOV direct, direct: this instruction will copy the contents source direct address to the destination direct address. E.g. MOV 20 H, 30 H. 20

21 a) Direct addressing mode: 1. Move the data into accumulator. 2. Move the data from accumulator to the memory location one by one. b) Register direct addressing mode without loop. 1. Move the data into accumulator. 2. Initialize any register Ro to memory location. 3. Move data of accumulator into the address pointed by Ro. 4. Increment Ro. 5. Repeat step 3 & 5 for 5 more times. 6. End. c) Register indirect addressing mode with loop 1. Move the data into accumulator. 2. Initialize any register Ro to memory location. Initialize R1 to Another memory address. 3. Move data of accumulator into the address pointed by Ro. 4. Increment Ro. 5. Decrement R1. 5. If R1 0, Repeat step 3, 4 & End. P o s t L a b A s s i gn m e n t s : 1. Explain the difference between MOV, MOVX, MOVC 2. Explain register bank in Explain difference between DPTR and PC 21

22 L a b S e s s i o n 1 3 T i t l e : WRITE A PROGRAM TO TOGGLE BITS FOR PORT 1. O b j e c t i v e : a) To familiarize with data transfer instruction of 8051 b) General Assembly Language Programming concepts of 8051 Pre-r e q u i s i t es : R e f e r e n c e : Theory: O b s e r v a t i o n s : 8051 data port details. Kenneth Ayala - Penram International ( II edition) 1) SJMP relative address It is the conditional jump after execution of SJMP instruction contents of relation address with PC to for jump location to which program control is transferred. 2) A call address (Absolute call) It calls address, subroutine located at a specific address. No flag affected. 1. Start 2. Move data 00H to the accumulator. 3. Move accumulator content to port. 4. Call delay. 5. Move data FF H to the accumulator. 6. Move accumulator content to port. 7. Call delay. 8. Jump to step Stop. Observe the port pin is toggling from 0 to 1 and again 0. P o s t L a b A s s i gn m e n t s : 1. Explain the various instructions used. 22

23 L a b S e s s i o n 1 4 T i t l e : W R I T E A PROGRAM TO SERIAL DATA TRANSFER TO TRANSMIT CHARACTER A O b j e c t i v e : a) To familiarize with data transfer instruction of 8051 b) General Assembly Language Programming concepts of 8051 Pre-r e q u i s i t es : R e f e r e n c e : Theory: 8051 data port details. Kenneth Ayala - Penram International (II edition) for communication between two computer systems we need to send and receive the data bits serially. The microcontroller 8051 has serial data communication circuit which uses a register in the SFR called SBUF to hold the data. The register SCON controls the data communication; the register PCON controls the data rates. The SBUF register comprise the two registers physically one of them is write only and is used to hold the data that is to be transmitted out from the microcontroller via the TXD pin, while the other is read only and holds the data that is receive from the external source via the RXD pin. The serial interface can be operated in four different modes mode 0, mode 1, mode 2, and mode 3 which can be configured using SCON register. Mode 0: Shift Register Mode 1: 8 bit UART. Mode2: 9 bit UART with fixed baud rate Mode3:9 bit UART with variable baud rate Mode 2 &3 has special provision for multiprocessor communication i.e. we can have master /slave configuration. ( M S B) ( LS B) SM0 SM1 SM2 REN T B8 R B8 TI RI Where SM0, SM1 specify the serial port mode, as follows: M0 SM1 Mode Description Ba u d Ra t e Shift Register Fosc/ bit UART Variable bit UART F o s c /64 or f osc bit UART Variable 23

24 1. Initializes TMOD register with value. 2. Initializes TH1 register with value -6 for baud Initialize SCON register with value. 4. Start the timer Move the immediate value p to SBUF register. 6. Wait till the TI flag is set. 7. Clear the TI flag. 8. To transmit data A continuously repeat 5, 6, and 7. P o s t L a b A s s i gn m e n t s : 1. Explain the various instructions used. 24

25 L a b S e s s i o n 1 5 T i t l e : T O G E N E R A T E O F 50 % D U T Y CYC L E US I NG O b j e c t i v e : Pre-r e q u i s i t es : R e f e r e n c e : T h e o r y : a) Understand 8051 Timers modes b ) U s e o f T C O N, T M O D a n d P C O N S F R s t o p r o g r a m t h e T i m e r s f o r a p a r t i c u l a r o v e r f l o w t i m e s c ) W r i t e I S R f o r T i m e r I n t e r r u p t Timer modes 2. SFRs TCON, TMOD, IE P C O N d e f i n i t i o n s 3. ISR locations Kenneth Ayala - P e n r a m I n t e r n a t i o n a l ( I I e d i t i o n ) T i m e r Mode 0: Setting timer X mode bits to 00b in the TMOD register results in using the THX register as an 8 - bit counter & TLX as a 5 bit counter; the pulse input is divided by 32d in TL so that TH counts the original oscillator frequency reduced by a total 384d. A s an example, the 6 MHz oscillator frequency would result in a final frequency to TH of Hz. The timer flag is set whenever THX go from FFh to 00h, or in.0164 seconds for 6 MHz. crystal if THX starts at 00h. Timer Mode 1: Mode 1 is similar to mode 0 except TLX is configured as a full 8-bit counter when the mode bits are set to 01b in TMOD. The timer flag would be set in seconds using a 6 MHz crystal. Timer Mode 2: setting the mode bits to 10b in TMOD configures the timer to use only the TLX counter as an 8 bit counter. T H X are used to hold a value that is loaded into TLX every time TLX overflow from FFh to 00h. The timer flag is also set when TLX overflows. This mode exhibits an auto reload feature: TLX will count up from the number in THX, overflow and initialized again with the contents of THX. Timer Mode 3: t i m e r 0, 1 may be programmed to be in mode 0, 1 or 2 independently of a similar mode for the other timer. This is not true for mode 3; the timers do not operate independently if mode 3 is chosen for timer 0. Placing timer 1 in mode 3 cause it to stop counting; the control bit TR1 and the timer 1 flag TF1 are then used by timer 0. Timer 0 in mode 3 becomes two completely separate 8 bit counters. 25

26 M ain Pr ogr am 1. Start 2. Initialize 8255 ports (A - o/p) 3. I n i t i a l i z e t i m e r 0 i n A u t o -reload mode 4. Enable Timer 0 Interrupt 5. Load count in Timer registers 6. Reset port A 7. Enable Timer Run 8. Go to 8051 in idle mode I n t er r u pt S er v i ce R ou t i n e O b s e r v a t i o n s : 1. Complement port A 2. Out to port A 3. Go to idle mode O b s e r v e t h e S q u a r e W a v e g e n e r a t e d o n C R O a n d c a l c u l a t e the Time Period between t w o Interrupts (T o b s.) Tc a l c = 12*(256 - Count in T H ) / 1 2 C o m p a r e T c a l c. w i t h T o b s. 26

27 L a b S e s s i o n 1 6 Title: Handshake operation of 8255 O b j e c t i v e : To study handshake operation of 8255 (Port A as a input port and port B a s an output port read a byte from port A and transfer to port B) T h e o r y : Algorithm: 1. Knowledge of operating modes of Handshake operation of 8255 Port A and the high part of port C may be programmed in one of three modes; port B and the lower part of port C may be programmed in one of two modes. The modes are: Mode 0- Basic I/O: Data written to the port is latched; data read from the port is read from the input pins.( this mode is identical to 8051 port operation.) Mode 1 Strobed I/O: This handshaking mode uses port A & B as I/O and port C to Generate handshaking signal to the devices connected to port A & B and an interrupt signal to the host microcontroller. Mode 2 Strobed bidirectional I/O: this mode is similar to mode 1 with the ability to use port A as a Bidirectional data Bus. Mode 1 & 2 require setting interrupt enable bits in the port C data register. These modes are intended to be used with intelligent peripherals such as printer. 1. To initialize 8255 port A as input port & port B as output port in mode 1 2. Enable INTRA using BSR mode. i.e. Make PC4 high. 3. Enable INTRN using BSR mode i.e. Make PC2 high. 4. Apply input to port A through LED. 5. Check if INTRA is present. 6. If INTRA is present input a byte from port A & increment data counter & store the data into memory 7. Read the status word of port B 8. Check INTRB. If INTRB is present & transfer a byte from memory location to port B P o s t L a b A s s i gn m e n t s : 1. Explain BSR mode of 8255 in detail. 2. Explain handshake operations of

28 28