SATHYABAMA UNIVERSITY DEPARTMENT OF ELECTRONICS AND INSTRUMENTATION LAB MANUAL
Transcription
SATHYABAMA UNIVERSITY DEPARTMENT OF ELECTRONICS AND INSTRUMENTATION LAB MANUAL
SATHYABAMA UNIVERSITY DEPARTMENT OF ELECTRONICS AND INSTRUMENTATION LAB MANUAL III YEAR B.E (EIE) – VI SEMESTER Academic Year 2013-2014 Batch (2011 – 2015) SECX4028 – Microprocessor & Microcontroller Lab Name : --------------------------------------------------------------------------- Reg.No :---------------------------------------------------------------------------- SECX4028 MICROPROCESSOR AND MICROCONTROLLER LAB LIST OF EXPERIMENTS: 1. Familiarization of 8085 trainer kit, 8086 trainer kit, 8051 trainer kit & 89C51 2. Addition & subtraction of 8 and 16 bits using 8085. 3. Multiplication & division 8 and 16 bits using 8085. 4. Interfacing of stepper motor using 8085. 5. Interfacing of traffic light using 8085. 6. Addition and subtraction of two 16 bit numbers using 8086. 7. Code converters using 8086. 8. Sorting of N numbers using 8086. 9. Arithmetic operation programs using 8051. 10. Interfacing of ADC using 8051. 11. Interfacing of DAC using 8051. 12. Addition and subtraction using 89C51. 13. Filling of internal memory using 89C51 EXPT.NO:1 FAMILIARIZATION OF 8085 TRAINER KIT, 8086 TRAINER KIT, 8051 TRAINER KIT & 89C51 1.1 Introduction of 8085: 1.1.1 Internal Block Diagram of 8085: INTEL 8085 is one of the most popular 8-bit microprocessor capable of addressing 64 KB of memory and its architecture is simple. The device has 40 pins, requires +5 V power supply and can operate with 3MHz single phase clock. ALU (Arithmetic Logic Unit): The 8085A has a simple 8-bit ALU and it works in coordination with the accumulator, temporary registers, 5 flags and arithmetic and logic circuits. ALU has the capability of performing several mathematical and logical operations. The temporary registers are used to hold the data during an arithmetic and logic operation. The result is stored in the accumulator and the flags are set or reset according to the result of the operation. The flags are affected by the arithmetic and logic operation. They are as follows: Sign flag After the execution of the arithmetic - logic operation if the bit D7 of the result is 1, the sign flag is set. This flag is used with signed numbers. If it is 1, it is a negative number and if it is 0, it is a positive number. Zero flag The zero flag is set if the ALU operation results in zero. This flag is modified by the result in the accumulator as well as in other registers. Auxiliary carry flag In an arithmetic operation when a carry is generated by digit D3 and passed on to D4, the auxiliary flag is set. Parity flag After arithmetic – logic operation, if the result has an even number of 1’s the flag is set. If it has odd number of 1’s it is reset. Carry flag If an arithmetic operation results in a carry, the carry flag is set. The carry flag also serves as a borrow flag for subtraction. Timing and control unit This unit synchronizes all the microprocessor operation with a clock and generates the control signals necessary for communication between the microprocessor and peripherals. The control signals RD (read) and WR (write) indicate the availability of data on the data bus. Instruction register and decoder The instruction register and decoder are part of the ALU. When an instruction is fetched from memory it is loaded in the instruction register. The decoder decodes the instruction and establishes the sequence of events to follow. Register array The 8085 has six general purpose registers to store 8-bit data during program execution. These registers are identified as B, C, D, E, H and L. they can be combined as BC, DE and HL to perform 16-bit operation. Accumulator Accumulator is an 8-bit register that is part of the ALU. This register is used to store 8-bit data and to perform arithmetic and logic operation. The result of an operation is stored in the accumulator. Program counter The program counter is a 16-bit register used to point to the memory address of the next instruction to be executed. Stack pointer It is a 16-bit register which points to the memory location in R/W memory, called the Stack. Communication lines 8085 microprocessor performs data transfer operations using three communication lines called buses. They are address bus, data bus and control bus. Address bus – it is a group of 16-bit lines generally identified as A0 – A15. The address bus is unidirectional i.e., the bits flow in one direction from microprocessor to the peripheral devices. It is capable of addressing 216 memory locations. Data bus – it is a group of 8 lines used for data flow and it is bidirectional. The data ranges from 00 – FF. Control bus – it consist of various single lines that carry synchronizing signals. The microprocessor uses such signals for timing purpose. 1.2 Introduction of 8086: 1.2.1 Internal Block Diagram of 8086: Figure shows a block diagram of the 8086 internal architecture. As shown in the figure, the 8086 microprocessor is internally divided into two separate functional units. These are the Bus Interface Unit (BIU) and the Execution Unit (EU). The BIU fetches instructions, reads data from memory and ports, and writes data to memory and I/O ports. The EU executes instructions that have already been fetched by the BIU. The BIU and EU function independently. The BIU interfaces the 8086 to the outside world. The BIU provides all external bus operations. The BIU contains segment registers, instruction pointer, instruction queue, and address generation bus control circuitry to provide functions such as fetching and queuing of instructions, and bus control. The BIU’s instruction queue is a First-In First-out (FIFO) group of registers in which up to six bytes of instruction code are perfected from memory ahead of time. This is done in order to speed up program execution by overlapping instruction fetch with execution. This mechanism is known as pipelining. If the queue is full and the EU does not request BIU to access memory, the BIU does not perform any bus cycle. On the other hand, if the BIU’s is not full and if it can store at least two bytes and the EU does not request it to access memory, the BIU may prefect instructions. However, if BIU is interrupted by EU for memory access while the BIU is in the process of fetching an instruction, the BIU first completes fetching and then services the EU: the queue allows the BIU to keep the EU supplied with perfected instructions without typing up the system bus. If an instruction such as Jump or subroutine call is encountered, the BIU will reset the queue and begin refilling after passing the new instruction to the EU. The BIU contains a dedicated adder, which is used to produce the 20-bit address. The bus control logic of the BIU generates all the bus control signals such as read and writes signals for memory and I/O. The BIU has four 16-bit segment registers. These are the Code Segment (CS) register, the Data Segment (DS) register, the Stack Segment (SS) register, and the Extra Segment (ES) register. The 8086’s one-megabyte memory is divided into segments of up to 64K bytes each. The 8086 can directly address four segments (256K byte within the 1 Mb memory) at a particular time. Programs obtain access to code and data in the segments by changing the segment register contents to point to the desired segments. All program instructions must be located in main memory pointed to by the 16-bit CS register with a 16-bit offset in the segment contained in the 16-bit instruction pointer (IP). The BIU computes the 20-bit physical address internally using the programmer-provided logical address (16-bit contents of CS and IP) by logically shifting the contents of CS four bits to left and then adding the 16-bit contents of IP. In other words, the CS is multiplied by 1610 by the BIU for computing the 20-bit physical address. This means that all instructions of a program are relative to the contents of the CS register multiplied by 16 and then offset is added provided by the 16-bit contents of IP. The BIU always inserts four Zeros for the lowest 4-bits of the 20-bit starting address (physical) of a segment. In the other words, the CS contains the base or start of the current code segment, and IP contains the distance or offset from this address to the next instruction byte to be fetched. Note that immediate data are considered as part of the code segment. The SS register points to the current stack. The 20-bit physical stack address is calculated from SS and SP for stack instruction such as PUSH and POP. The programmer can use the BP register instead of SP for accessing the stack using the based addressing mode. In this case, the 20-bit physical stack address is calculated from BP and SS. The DS register points to the current data segment; operands for most instructions are fetched from this segment. The 16-bit contents of Source Index (SI) or Destination Index (DI) are used as offset for computing the 20-bit physical address. The ES register points to the extra segment in which data (in excess of 64k pointed to by DS) is stored. String instructions always use ES and DI to determine the 20-bit physical address for the destination. The segment can be continuous, partially overlapped, fully overlapped, or disjoint. An example of how five (segment 0 through segment 4) may be stored in physical memory are shown. In the above SEGMENTS 0 and 1 are contiguous (adjacent) ,SEGMENTS 1 an d 2 are partially overlapped, SEGMENTS 2 and 3 are fully overlapped, and SEGMENTS 2 and 4 are disjoint. Every segment must start on 16-byte memory boundaries. Typical examples of values of segments should then be selected based on physical addresses starting at 0000016, 0001016, 0002016, 0003016… FFFF016. A physical memory location may be mapped into (contained in) one or more logical segments. Many applications can be written to simply initialize the segment and then forget them. A segment can be pointed to by more than one segment register. For example, DS and ES may point to the same segment in memory if a string located in that segment is used as a source segment in one string instruction and as a destination segment in another string instruction. Note that for string instructions, ES must point to a destination segment. It should be pointed out that codes should not be written within 6 bytes of the end of physical memory. Failure to comply with this guideline may result in an attempted opcode fetch from nonexistent memory, hanging the CPU if READY is not returned. One example of four currently addressable segments is shown below: The EU decodes and executes instructions. A decoder in the EU control system translates instructions. The EU has a 16-bit ALU for performing arithmetic and logic operations. The EU has eight 16-bit general registers. These are AX, BX, CX, DX, SP, BP, SI, and DI. The 16-bit registers AX, BX, CS, and DX can be used as two 8-bit registers (AH, AL, BH, BL, CH, CL, DH, DL). For example, the 16-bit register DX can be considered as two 8-bit registers DH (high byte of DX) and DL (low byte of DX). The general-purpose registers AX, BX, CX, and DX are named after special functions carried out by each one of them. For example, the AX is called the 16-bit accumulator while the AL is the 8-bit accumulator. The use of accumulator registers is assumed by some instructions. The Input/output (IN or OUT) instructions always use AX or AL for inputting/outputting 16- or 8-bit data to or from and I/O port. Multiplication and division instructions also use AX or AL. The AL register is the same as the 8085 A register. BX register is called the base register. This is the only general-purpose register, the contents of which can be used for addressing 8086 memory. All memory references utilizing these register contents for addressing use Ds as the default segment register. The BX register is similar to 8085 HL register. In other words, 8086 BH and BL are equivalent to 8085 H and L registers, respectively. The CX register is known as the counter register. This is because some instructions such as shift rotate, and loop instructions use the contents of CX as a counter. For example, the instruction LOOP START will automatically decrement CX by 1 without affecting flags and will check if [CX] =0. If is zero, the 8086 executes the next instruction; otherwise the 8086 branches to the label START. The data register DX is used to hold high 16-bit result (data) in 16* 16 multiplications or high 16-bit dividend (data) before a 32 16 division and the 16-bit remainder after the division. The two pointer registers, SP (stack pointer) and BP (base pointer), are used to access data in stack segment. The SP is used as an offset from the current SS during execution of instructions. That involve stack segment in external memory. The SP contents are automatically updated (incremented or decremented) due to execution of POP or PUSH instruction. The base pointer contains an offset address in the current SS. This offset is used by the instructions utilizing the based addressing mode. The FLAG register in the EU holds the status flags typically after an ALU operation. The 8086 have six one-bit flags. AF (Auxiliary carry flag) is used by BCD bit) into the high nibble or borrow from the high nibble into the low nibble of the low-order 8-bit of a 16-bit number. CF (Carry Flag) is set if there is a carry from addition or borrow from subtraction. OF (Overflow Flag) is set if there is an arithmetic overflow, that is, if the size of the result exceeds the capacity of the destination location. An interrupt on overflow instructions is available which will generate an interrupt in this situation. SF (Sign Flag) is set if the most significant bit of the result is one (Negative) and is cleared to zero for non-negative result. PF (Parity Flag) is set if the result has even parity; PF is zero for odd parity of the result. ZF (Zero Flag) is set if the result is zero; ZF is zero for non-zero result. The 8086 has three control bits in the flag register which can be set or reset by the programmer: setting DF (Direction Flag) to one causes string instructions to auto decrement and clearing DF to zero causes string instructions to auto increment. Setting IF (Interrupt Flag) to one causes the 8086 to recognize external mask able interrupts; clearing IF to zero disables these interrupts. Setting TF (Trace Flag) to one places the 8086 in the single-step mode. In this mode, the 8086 generate an internal interrupt after execution of each instruction. The user can write a service routine at the interrupt address vector to display the desired registers and memory locations. The user can thus debug a program. ADDRESSING MODES OF 8086 Addressing mode indicates a way of locating data or operands. Depending upon the data types used in the instruction and the memory addressing modes, any instruction may belong to one or more addressing modes or some instruction may not belong to any of the addressing modes. Thus the addressing modes describe the types of operands and the way they are accessed for executing an instruction. Here, we will present the addressing modes of the instructions depending upon their types. According to the flow of instruction execution, the instructions may be categorized as (i) Sequential control flow instructions and (ii) Control transfer instructions. Sequential control flow instructions are the instructions, which after execution, transfer control to the next instruction appearing immediately after it (in the sequence) in the program. For example, the arithmetic, logical, data transfer and processor control instructions are sequential control flow instructions. The control transfer instructions, on the other hand, transfer control to some predefined address somehow specified in the instruction after their execution. For example, INT, CALL, RET and JUMP instructions fall under this category. The addressing modes for sequential control transfer instructions are explained as follows: 1. Immediate: In this type of addressing, immediate data is a part of instruction, and appears in the form of successive byte or bytes. Example: MOV AX, 0005H In the above example, 0005H is the immediate data. The immediate data may be 8-bit or 16bit in size. 2. Direct: In the direct addressing mode, a 16-bit memory address (offset) is directly specified in the instruction as a part of it. Example: MOV AX, [5000H] Here, data resides in a memory location in the data segment, whose effective address may be computed using 5000H as the offset address and content of DS as segment address. The effective address, here, is 10H*DS+5000H. 3. Register: In register addressing mode, the data is stored in a register and it is referred using the particular register. All the registers, except IP, may be used in this mode. Example: MOV BX, AX. 4. Register Indirect: Sometimes, the address of the memory location, which contains data or operand, is determined in an indirect way, using the offset registers. This mode of addressing is known as register indirect mode. In this addressing mode, the offset address of data is in either BX or SI or DI registers. The default segment is either DS or ES. The data is supposed to be available at the address pointed to by the content of any of the above registers in the default data segment. Example: MOV AX, [BX] Here, data is present in a memory location in DS whose offset address is in BX. The effective address of the data is given as 10H*DS+ [BX]. 5. Indexed: In this addressing mode, offset of the operand is stored in one of the index registers. DS and ES are the default segments for index registers SI and DI respectively. This mode is a special case of the above discussed register indirect addressing mode. Example: MOV AX, [SI] Here, data is available at an offset address stored in SI in DS. The effective address, in this case, is computed as 10H*DS+ [SI]. 6. Register Relative: In this addressing mode, the data is available at an effective address formed by adding an 8-bit or 16-bit displacement with the content of any one of the registers BX, BP, SI and DI in the default (either DS or ES) segment. The example given before explains this mode. Example: MOV Ax, 50H [BX] Here, effective address is given as 10H*DS+50H+ [BX]. 7. Based Indexed: The effective address of data is formed, in this addressing mode, by adding content of a base register (any one of BX or BP) to the content of an index register (any one of SI or DI). The default segment register may be ES or DS. Example: MOV AX, [BX] [SI] Here, BX is the base register and SI is the index register. The effective address is computed as 10H*DS+ [BX] + [SI]. 8. Relative Based Indexed: The effective address is formed by adding an 8-bit or 16-bit displacement with the sum of contents of any one of the bases registers (BX or BP) and any one of the index registers, in a default segment. Example: MOV AX, 50H [BX] [SI] Here, 50H is an immediate displacement, BX is a base register and SI is an index register. The effective address of data is computed as 160H*DS+ [BX] + [SI] + 50H. For the control transfer instructions, the addressing modes depend upon whether the destination location is within the same segment or a different one. It also depends upon the method of passing the destination address to the processor. Basically, there are two addressing modes for the control transfer instructions, viz. inter-segment and intra-segment addressing modes. If the location to which the control is to be transferred lies in a different segment other than the current one, the mode is called inter-segment mode. If the destination location lies in the same segment, the mode is called intra-segment. 9. Intra-segment direct mode: In this mode, the address to which the control is to be transferred lies in the same segment in which the control transfers instruction lies and appears directly in the instruction as an immediate displacement value. In this addressing mode, the displacement is computed relative to the content of the instruction pointer IP. The effective address to which the control will be transferred is given by the sum of 8 or 16 bit displacement and current content of IP. In case of jump instruction, if the signed displacement (d) is of 8 bits (i.e. –128<d<+128), we term it as short jump and if it is of 16 bits (i.e. –32768<+32768), it is termed as long jump. 10. Intra-segment Indirect Mode: In this mode, the displacement to which the control is to be transferred is in the same segment in which the control transfer instruction lies, but it is passed to the instruction indirectly. Here, the branch address is found as the content of a register or a memory location. This addressing mode may be used in unconditional branch instructions. 11. Inter-segment Direct Mode: In this mode, the address to which the control is to be transferred is in a different segment. This addressing mode provides a means of branching from one code segment to another code segment. Here, the CS and IP of the destination address are specified directly in the instruction. 12. Inter-segment Indirect Mode: In this mode, the address to which the control is to be transferred lies in a different segment and it is passed to the instruction indirectly, i.e. contents of a memory block containing four bytes, i.e. IP (LSB), IP (MSB), CS (LSB) and CS (MSB) sequentially. The starting address of the memory block may be referred using any of the addressing modes, except immediate mode. 1.3 INTRODUCTION TO 8051: 1.3.1 Internal Block Diagram of 8051: MICROCONTROLLERS i. ii. CPU + I/O + TIMER(S) [+ ROM] [+ RAM] LOW TO MODERATE PERFORMANCE ONLY iii. LIMITED RAM SPACE, ROM SPACE AND I/O PINS iv. EPROM VERSION AVAILABLE v. vi. vii. LOW CHIP-COUNT TO IMPLEMENT A SMALL SYSTEM LOW-COST AT LARGE QUANTITIES DEVELOPMENT TOOLS READILY AVAILABLE AT REASONABLE COST PROGRAM STATUS WORD: PSW (program status word) register summary BIT PSW.7 PSW.6 PSW.5 PSW.4 PSW.3 SYMBOL CY AC F0 RSI RS0 ADDRESS D7H D6H D5H D4H D3H PSW.2 PSW.1 PSW.0 OV -P D2H D1H D0H BIT DESCRIPTION Carry flag Auxiliary carry flag Flag 0 Register bank select 1 Register bank select 0 00 = bank 0:addresses 00H01 = bank 0:addresses 08H10 = bank 0:addresses 10H11 = bank 0:addresses 18HOverflow flag Reserved Even parity flag FOUR BANKS OF 8 BYTE-SIZED REGISTERS, R0 TO R7 ADDRESSES ARE: 1. 18 - 1F FOR BANK 3 2. 10 - 17 FOR BANK 2 3. 08 - 0F FOR BANK 1 4. 00 - 07 FOR BANK 0 (DEFAULT) 1.4 INTRODUCTION OF 89C51 MICROCONTROLLER:1.4.1 INTERNAL BLOCK DIAGRAM OF 89C51:- The ATmel 89C51 is a low-power, high-performance CMOS 8-bit microcomputer with 4K bytes of Flash programmable and erasable read only memory (PEROM). The ATmel 89C51 device is manufactured using Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C51 is a powerful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications. The ATmel 89C51 provides the following standard features: 4K Bytes of Flash, 128 bytes of RAM, 32 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator and clock circuitry. In addition, the 89C51 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port and interrupt system to continue functioning. The AT89C51 Power-down Mode saves the RAM contents but freezes the oscillator disabling all other chip functions until the next hardware reset. Compatible with MCS-51 Products 4K Bytes of In-System Reprogrammable Flash Memory Fully Static Operation: 0 Hz to 24 MHz Three-level Program Memory Lock 128 x 8-bit Internal RAM 32 Programmable I/O Lines Two 16-bit Timer/Counters Six Interrupt Sources Programmable Serial Channel Low-power Idle and Power-down Modes 40-pin DIP EXPT NO: 2a ADDITION OF TWO 8 BIT & 16 BIT NUMBERS USING 8085 AIM: To add two 8 bit numbers stored at consecutive memory locations. ALGORITHM: 8 bit addition: 1. Load the addend into accumulator from memory. 2. Move the data into one of the registers. 3. Load the augend into accumulator from memory. 4. Perform addition operation. 5. Display the result. 16 bit addition: 1. Load the augend into HL registers pair. 2. Load the addend into another register pair. 3. Perform addition operation using DAD instruction. 4. Display the result. FLOWCHART: PROGRAM: ADDRESS RESULT: LOOP MNEMONICS OPCODES COMMENTS EXPT NO: 2b SUBTRACTION OF TWO 8 BIT & 16 BIT NUMBERS USING 8085 AIM: To perform subtraction of two 8 bit & two16 bit data using 8085. ALGORITHM: 8 bit subtraction: 1. Load the subtrahend into accumulator from memory. 2. Move the data into one of the registers. 3. Load the minuend into accumulator from memory. 4. Perform subtraction operation. 5. Display the result. 16 bit subtraction: 1. Load the subtrahend into HL registers pair. 2. Load the minuend into another register pair. 3. Perform subtraction operation of least significant 8 bits. 4. Perform subtraction operation of most significant 8 bits taking borrow into account if any. 5. Display the result. FLOW CHART. PROGRAM: ADDRESS RESULT LOOP MNEMONICS OPCODES COMMENTS EXPT NO: 3a MULTIPLICATION OF 8-BIT & 16-BIT NUMBERS USING 8085 AIM: To perform multiplication of two 8 bit and 16 bit data using repeated addition method. ALGORITHM: 8 bit multiplication: 1. Load the multiplicand into one register 2. Load the multiplier into another register. 3. Clear the accumulator. 4. Add the multiplier register with accumulator. 5. Decrement the multiplicand register. 6. Repeat step 4 & 5 until multiplicand register becomes zero. 7. Display the result. 16 bit multiplication: 1. Clear HL and another register pair, one for addition & another for carry. 2. Load the multiplicand and multiplier in two different register pairs. 3. Add the multiplier with HL. 4. If Carry occurs, increment the register pair for carry. 5. Decrement the multiplicand register pair. 6. Repeat steps 3, 4, 5 until the multiplicand register pair becomes zero. 7. Display the result and the carry. FLOWCHART. PROGRAM: ADDRESS RESULT : LOOP MNEMONICS OPCODES COMMENTS EXPT NO: 3b DIVISION OF TWO 8 BIT AND 16 BIT DATA USING 8085 AIM: To perform division of two 8 bit data ALGORITHM: 8 bit Division: 1. Load the divider into one register and accumulator. 2. Load the divisor into another register. 3. Perform subtraction operation with divisor register. 4. Increment the register meant for quotient. 5. Repeat the steps 3 and 4 until the accumulator is less than the divisor. 6. Display the quotient and remainder. 16-Bit Division 1. Load the divider into one register and accumulator. 2. Load the divisor into another register 3. Perform subtraction operation with divisor register. 4. Increment the register meant for quotient. 5. Repeat the steps 3 and 4 until the accumulator is less than the divisor 6. Display the quotient and remainder. FLOWCHART: PROGRAM: ADDRESS RESULT: LOOP MNEMONICS OPCODES COMMENTS EXPT.NO: 4 INTERFACING OF STEPPER MOTOR WITH 8085 AIM: To write a program for interfacing a stepper motor with 8085 microprocessor. THEORY: A motor in which the rotor is able to assume only discrete stationary angular position is a stepper motor. The rotary motion occurs in a step-wise manner from one equilibrium position to the next. Stepper Motors are used very wisely in position control systems like printers, disk drives, process control machine tools, etc. The basic two-phase stepper motor consists of two pairs of stator poles. Each of the four poles has its own winding. The excitation of any one winding generates a North Pole. A South Pole gets induced at the diametrically opposite side. The rotor magnetic system has two end faces. It is a permanent magnet with one face as South Pole and the other as North Pole. The Stepper Motor windings A1, A2, B1, and B2 are cyclically excited with a DC current to run the motor in clockwise direction. By reversing the phase sequence as A1, B2, A2, B1, anticlockwise stepping can be obtained. 2-PHASE SWITCHING SCHEME: In this scheme, any two adjacent stator windings are energized. The switching scheme is shown in the table given below. This scheme produces more torque. ANTICLOCKWISE CLOCKWISE STEP A1 A2 B1 B2 DATA STEP A1 A2 B1 B2 DATA 1 1 0 0 1 9h 1 1 0 1 0 Ah 2 0 1 0 1 5h 2 0 1 1 0 6h 3 0 1 1 0 6h 3 0 1 0 1 5h 4 1 0 1 0 Ah 4 1 0 0 1 9h ADDRESS DECODING LOGIC: The 74138 chip is used for generating the address decoding logic to generate the device select pulses; CS1 & CS2 for selecting the IC 74175.The 74175 latches the data bus to the stepper motor driving circuitry. Stepper Motor requires logic signals of relatively high power. Therefore, the interface circuitry that generates the driving pulses uses silicon Darlington pair transistors. The inputs for the interface circuit are TTL pulses generated under software control using the Microcontroller Kit. The TTL level of pulse sequence from the data bus is translated to high voltage output pulses using a buffer 7407 with open collector. ALGORITHM: 1. Initialize the memory mapped I/O address for control word to data pointer register. 2. The control word 80 is transferred to accumulator. 3. The content of accumulator is sent to memory mapped I/O address for control word and the microprocessor gets programmed for port A, B, C as output port, I/O mode, and simple I/O mode. 4. Initialize the memory mapped I/O address for Port A to data pointer register. 5. Initialize the Accumulator with the Hex code for rotating both motor in clockwise direction. 6. The data is sent to Port A in order to move the stator from one step position to other there would be some time taken so call for time delay routine. 7. Initialize the accumulator with the second hex code for rotation of stepper motor. 8. The data is sent to port A in order to move the stator from one step position to other would be some time taken so call for time delay routine. 9. Initialize the accumulator with the third Hex code for rotation of stepper motor. 10. The data is sent to port A in order to retain the stator from one step position to other there would be some time taken so call for time delay routine. 11. initialize the accumulator with the last hex code for rotation of stepper motor 12. The data is sent to Port A, in order to move the stator from one step position to other there should be some time taken so call for time delay routine. 13. To make the motor rotate continuously we normally give an infinite loop so that the loop repeats from step 4. ALGORITHM FOR DELAY ROUTINE: 1. Initialize the register R1 with immediate data 33 2. Initialize the register Ro with immediate data 33 3. The content of R1 register is decremented by 1 until it reaches zero to attain desired delay so repeat step 3. 4. The content of Ro register is decremented by 1 until it reaches zero to attain desired delay so repeat step 2. 5. The called routine goes back after being executed to main program 6. Program comes to an end. ALGORITHM FOR ANTICLOCKWISE DIRECTION: The sequence of data is reversed so that the motor can be rotated in anticlockwise direction. PROGRAM: ADDRESS RESULT: OPCODE MNEMONICS COMMENT EXPT.NO:5 INTERFACING OF TRAFFIC LIGHT USING 8085 AIM: To write an Assembly language Program for traffic light controller. EQUIPMENT REQUIRED: 8085 microprocessor kit, Power Supply. ALGORITHM: 1. Start. 2. Write the control word to initialize 8085.Obtain the data for each direction and store in the memory. 3. Initialize a counter to indicate the number of directions. 4. Initialize HL Pair to the starting address of the data. 5. Check the result. 6. Decrement the counter and repeat step 3 till counter becomes zero. 7. Stop. PROGRAM: ADDRESS RESULT: OPCODE MNEMONICS COMMENT EXPT.NO: 6a ADDITION OF TWO 16 BIT NUMBERS USING 8086 AIM: To add two 16 bit numbers using 8086. ALGORITHM: 1. Move the addend into accumulator. 2. Add the accumulator data with augend in the specified memory location. 3. Move the result into desired memory location. 4. Display the result FLOWCHART: PROGRAM: ADDRESS OPCODE RESULT: MNEMONICS COMMENT EXPT.NO: 6b SUBTRACTION OF TWO 16 BIT NUMBERS AIM: To subtract two 16 bit numbers using 8086. ALGORITHM: 1. Move the subtrahend into accumulator. 2. Subtract the minuend from accumulator content. 3. Complement the accumulator content 4. Increment the accumulator content 5. Move the result from accumulator to specified location 6. Stop the program. FLOWCHART: PROGRAM: ADDRESS OPCODE RESULT: MNEMONICS COMMENT EXPT.NO:7a CODE CONVERSION USING 8085 AIM: To convert the given data in ASCII to HEX. ALGORITHM: 1. 2. 3. 4. 5. 6. 7. Load the given data in accumulator. Compare the given data with 30 H. If the given data is larger than 30 but less than 3A then go to step 5 If less than 30 or greater than 45, display invalid data FF. Subtract 30 H from the given data. Compare accumulator data with 0A, (A) > 0A subtract 07 Store the results FLOWCHART: PROGRAM: ADDRESS RESULT: LOOP MNEMONICS OPCODES COMMENTS EXPT.NO:7b CODE CONVERSION AIM: To convert the given data in HEX to ASCII ALGORITHM: 1) 2) 3) 4) 5) 6) 7) Load the given data in accumulator. Compare the given data with 09 H. If the given data is less than 09H Add 30H, goto step 7 If the given data is greater than 09 Add 37H. Store the result. FLOWCHART: PROGRAM: ADDRESS RESULT: LOOP MNEMONICS OPCODES COMMENTS EXPT.NO:7c CODE CONVERSION AIM: To convert the given data in BCD to HEX ALGORITHM: 1) 2) 3) 4) 5) 6) 7) 8) Load the given data in accumulator and two registers To separate the Least significant 4 bits, perform AND operation with OF H. Store the corresponding result (units place) in a register. From the original data, separate the most significant 4 bits by performing AND operation with FO. To put these 4 bits in LSB position, perform Rotate Right operation 4 times. Call Subroutine to multiply with data OAH. The result of above operation will be in accumulator. (Tens place). Add the two results (units place & tens place). Display the final result. Subroutine: 1. Load the multiplicand into one register 2. Load the multiplier into another register. 3. Clear the accumulator. 4. Add the multiplier register with accumulator. 5. Decrement the multiplicand register. 6. Repeat step 4 & 5 until multiplicand register becomes zero. 7. Store the result FLOWCHART: PROGRAM: ADDRESS RESULT: LOOP MNEMONICS OPCODES COMMENTS EXPT.NO:7d CODE CONVERSION AIM: To convert the given data in HEX to BCD. ALGORITHM: 1. Load the data into accumulator and another register. 2. To get the Hundredth place digit, perform division by repeated subtraction subtract 64H (100)from the given data. 3. Perform subtraction until the result becomes less than 64H. 4. Count the number of subtractions performed, i.e, and the quotient gives the Hundredth place value. 5. Once the result of subtraction becomes less than 64 H, get the tenth place digit by dividing the obtained result with 0A. i.e, Perform repeated subtraction with 0A, until the result of subtraction becomes less than 0A. 6. The remainder of the above division gives the units place digit. Store it in a register. 7. The quotient obtained is rotated left 4 times to obtain the tenth place digit. 8. Add the tenth & units place digits. Display the result. 9. Display the hundredth place digit. FLOWCHART: PROGRAM: ADDRESS RESULT: LOOP MNEMONICS OPCODES COMMENTS EXPT.NO: 8. SORTING OF N NUMBERS IN ASCENDING ORDER USING 8086 AIM: To write an ALP for arranging the numbers in ascending order ALGORITHM: 1. 2. 3. 4. 5. 6. Move the counter which is the number of comparisons to CX register. Initialize BX with starting address of array. Decrement the counter value by one and store it to DX register. Move the first element of array to accumulator. Compare it with the next one. If the succeeding element is not greater than the first, exchange the two elements. 7. Increment BX twice. 8. Decrement counter register DX. 9. Repeat steps 4 to 8 till counter register DX =0. 10. Decrement counter CX. 11. Repeat steps 2 to 10 till CX=0. 12. Stop. FLOWCHART: PROGRAM: ADDRESS OPCODE RESULT: MNEMONICS COMMENT EXPT.NO: 8b SORTING OF N NUMBER IN DESCENDING ORDER USING 8086 AIM: To write an ALP for arranging the numbers in descending order. ALGORITHM: 1. Move the counter value, which is the number of comparisons to CX register. 2. Initialize BX with starting address of array. 3. Decrement the counter value by one and store it to DX register. 4. Move the first element of array to accumulator. 5. Compare it with the next one. 6. If the succeeding element is greater than the first, exchange the two elements. 7. Increment BX twice. 8. Decrement counter register DX. 9. Repeat steps 4 to 8 till counter register DX =0. 10. Decrement counter CX. 11. Repeat steps 2 to 10 till CX=0. 12. Stop. FLOWCHART: PROGRAM: ADDRESS OPCODE RESULT: MNEMONICS COMMENT EXPT.NO: 9a ADDITION OF TWO 8 BIT AND 16 BIT DATA USING MICROCONTROLLER. AIM: To perform addition of two 8 bit and 16 bit data using microcontroller. ALGORITHM: 8 bit addition: 1. Load the addend into accumulator from memory. 2. Move the data into one of the registers. 3. Load the augend into accumulator from memory. 4. Perform addition operation. 5. Display the result. 16 bit addition: 1. Add LSB of data 2. Store the result in the memory location pointed by DPTR 3. Increment DPTR 4. Add MSB of the data 5. Store the result in the memory location pointed by DPTR 6. Display the result. FLOWCHART: PROGRAM: ADDRESS RESULT: LOOP MNEMONICS COMMENTS EXPT.NO: 9B SUBTRACTION OF TWO 8 BIT AND 16 BIT DATA USING MICROCONTROLLERS AIM: To perform subtraction of two 8 bit and 16 bit data using microcontroller. ALGORITHM: 8 bit subtraction: 1. Load the subtrahend into accumulator from memory. 2. Move the data into one of the registers. 3. Load the minuend into accumulator from memory. 4. Perform subtraction operation. 5. Display the result. 16 bit subtraction: 1. Subtract LSB of data2 from LSB of data1 2. Store the result in the memory pointed by DPTR 3. Increment DPTR 4. Subtract MSB of data 2 from LSB of data1 5. Store the result in the memory location pointed by DPTR 6. Display the result. FLOWCHART: PROGRAM: ADDRESS RESULT: LOOP MNEMONICS COMMENTS EXPT.NO:9c MULTIPLICATION AND DIVISION USING MICROCONTROLLERS 8051 AIM: To perform multiplication of two 8 bit number using 8051. ALGORITHM: 8 bit multiplication: 1. Load the multiplicand into one register (A). 2. Load the multiplier into another register (B). 3. Perform multiplication operation 4. Resultant LSB will be stored in A 5. Resultant MSB will be stored in B 6. Display the result. FLOWCHART: PROGRAM: ADDRESS RESULT: LOOP MNEMONICS COMMENTS EXPT.NO: 9d DIVISION OF 8 BIT DATA USING MICROCONTROLLERS AIM: To perform division of 8 bit data ALGORITHM: 8 bit division: 1. Store the dividend and divisor in location pointed to by R0 and R1 respectively. 2. Move them to accumulator and register B 3. Divide them using DIV instruction 4. Store quotient and remainder in desired locations 5. End the program FLOWCHART: PROGRAM: ADDRESS RESULT: LOOP MNEMONICS COMMENTS EXPT. NO: 10 INTERFACING OF ADC WITH MICROCONTROLLERS AIM: To study the operation of ADC and to write the ALP to convert analog to digital values. THEORY: The ADC-01 analog to digital converter card interfaces with any microprocessor kit. It is used to develop digital signal processing and real time process control applications. The ADC-01 card incorporates monolithic CMOS 8 bit successive approximation (microprocessor compatible) analog to digital converter ADC-0809. This converter features a high impedance chopper stabilized comparator, its resolution is 8 bits and conversion time is 100 microseconds. It has a programmable clock oscillator which generates 100 KHz clock signal. The reference voltage is 5.12 Volts. Power Connection: Green : +12 V Blue : - 12 V Black : Ground. Block Diagram: Since only one channel is used of the analog multiplexer, the channel select address of ADC - 0809 are not interfaced with the 8255 IC. The 8255 is defined in mode 0. Port A is used for reading the ADC data , defined in the Input mode, Port B is used to apply control signals, and is defined in output mode and Port C is used to read the status and it is defined in input mode. PB2- Oscillator ( logic 1) PB0-SOC Pc0 / PC7 – EOC DYNA -85 Address Details Port A- 10 Port B -11 Port C- 12 Control Register – 13 ALGORITHM: 1. 2. 3. 4. 5. 6. 7. 8. 9. Initialize the ports of 8255. Enable the start of conversion (SOC) Latch the address for proper channel by making ALE high. Check the end of conversion ( EOC) Enable the output of ADC ( OE). Read the converted digital data. Call the display subroutine. Call the delay subroutine. Goto step 2 for taking the next sample. PROGRAM: ADDRESS RESULT: LOOP MNEMONICS COMMENTS EXPT.NO: 11 INTERFACING OF DAC WITH MICROCONTROLLERS AIM: To study the DAC and to write the ALP to convert digital values to analog and to generate the following waveforms: 1. Square 2.Ramp 3.Triangular. THEORY: The DMS- DAC 01 A Digital to Analog converter card interfaces with any microprocessor kit. It is used to implement analog and digital signal processing and real time process control applications on DAC -01 A interface card. DAC-01 A is designed around DSC-0800 monolithic 8 bit high speed current output digital to analog converter featuring 100 nsecs settling time, (typical). DAC -01 A has adjustable voltage reference which permits full scale voltage. The Vref to full scale current matching of better than ± LSB gives ± LSB full scale error. RED : + 5V. GREEN : +12 V BLUE YELLO W : -12V BLACK : +30 V :GROUN D ALGORITHM: Square waveform: 1. 2. 3. 4. 5. 6. 7. 8. Initialise 8255 (for DAC) Move the data 00 (low value)to accumulator OUT through Port A Call delay Move the data FF (high value) to accumulator. OUT through Port A Call delay Goto step 2. Ramp Waveform: 1. Initialise the 8255 in mode 0. 2. Move the data 00 to the accumulator. 3. OUT the data through port. 4. Increment the accumulator. 5. OUT the data through port. 6. If content of accumulator = FF, goto step 2 7. Otherwise goto step 4. Triangular waveform 1. Initialise the 8255 in mode 0. 2. Move the data 00 to the accumulator. 3. OUT the data through port. 4. Increment the accumulator. 5. OUT the data through port. 6. If content of accumulator = FF, goto step 8 7. Otherwise goto step 4. 8. Decrement the contents of accumulator. 9. OUT through port. 10. If content of accumulator = 00, then goto step 4. 11. Otherwise goto step 8. PROGRAM: ADDRESS RESULT: LOOP MNEMONICS COMMENTS EXPT.NO:12a ADDITION OF TWO 8-BIT NUMBERS USING 89C51. AIM: To write and execute an assembly language program to add two 8-bit numbers using microcontroller 89C51. APPARATUS REQUIRED 1. Microcontroller kit 2. PC with WinXtalk software ALGORITHM: 1. 2. 3. 4. 5. Start the program Move the Data 1 to the accumulator Add the Data 2 with the data 1 stored in the accumulator Set the DPTR as 8300 in Ram address location. Move the result which is in accumulator to the 8300 address location. 6. Stop the program. PROGRAM ADDRESS RESULT : LOOP MNEMONICS COMMENTS EXPT.NO:12b SUBTRACTION OF TWO 8-BIT NUMBERS 89C51. USING AIM: To write and execute an assembly language program to subtract two 8-bit numbers using microcontroller. APPARATUS REQUIRED 1. Microcontroller kit 2. PC with WinXtalk software ALGORITHM: 1. Load the subtrahend into accumulator from memory 2. Move the data into one of the registers 3. Load the minuend into accumulator from memory 4. Perform subtraction operations 5. Display the result. PROGRAM ADDRESS RESULT: LOOP MNEMONICS COMMENTS EXPT.NO: 13 FILLING OF INTERNAL MEMORY USING 89C51 AIM: To fill the internal memory 40 and subsequent locations with content of A register. ALGORITHM : 1. 2. 3. 4. 5. 6. 7. 8. PROGRAM ADDRESS RESULT: The register R0 is assigned with immediate data 06. Store the content of Accumulator with 56. Assign an internal data memory address 40 to register R1. Transfer the content of Accumulator to internal l memory address 40. Content of R1 register is incremented by one. The content of data pointer register is incremented by one. The loop executes until the content of R0 register reaches 0. The program gets terminated. LOOP MNEMONICS COMMENTS