EMBEDDED SYSTEMS www.maheshelectronics.wordpress.com
UNIT – 1 PART-A Embedded Systems – Introduction (Definition, Applications and Classification) Features and architecture considerations(ROM,RAM,TIMERS…) RISC Vs. CISC Von-Neumann & Harvard Architecture Memory mapped I/O and Isolated I/O Little-Endian and Big-Endian PART-B Low Power RISC- MSP 430 : Introduction & Variants of MSP 430 family MSP430F2013 - Block diagram & features Memory map of MSP430 MSP430 –CPU architecture & registers Addressing modes of MSP430 Instruction formats & Instruction Timings of MSP430 Instruction set of MSP430 Sample Embedded system on MSP430 www.maheshelectronics.wordpress.com
INTRODUCTION TO EMBEDDED SYSTEMS Definition :An embedded system is an electronic/electro-mechanical system designed to perform a specific function and is combination of both hardware and firmware (software). The program instructions written for embedded systems are referred to as firmware, and are stored in Read-Only-Memory or Flash memory. www.maheshelectronics.wordpress.com
INTRODUCTION TO EMBEDDED SYSTEMS Purpose of Embedded System Data Collection/Storage/Representation Data communication Data processing Monitoring Control Application specific user interface www.maheshelectronics.wordpress.com
INTRODUCTION TO EMBEDDED SYSTEMS Applications of Embedded Systems Household appliances Automotive industry Home automation & security systems Telecom Computer peripherals Computer networking systems Healthcare Banking & Retail Card Readers Measurements & Instrumentation Missiles and Satellites Robotics Motor control systems Entertainment systems Signal & Image processing www.maheshelectronics.wordpress.com
INTRODUCTION TO EMBEDDED SYSTEMS Classification of Embedded Systems: The classification of embedded system is based on following criteria's: On generation On complexity & performance www.maheshelectronics.wordpress.com
INTRODUCTION TO EMBEDDED SYSTEMS Classification based on generation 1. First generation(1G):8-bit μp and 4-bit μc. 2. Second generation(2G):16-bit μp and 8-bit μc. 3. Third generation(3G):32-bit μp & 16-bit μc. 4. Fourth generation(4G):64-bit μp & 32-bit μc. www.maheshelectronics.wordpress.com
INTRODUCTION TO EMBEDDED SYSTEMS Classification based on Complexity and performance 1. Small-scale Simple applications where the performance requirements are not time-critical. Built around low performance and low cost 8 or 16 bit μp/μc. 2. Medium-scale Slightly complex in hardware and firmware requirement. Built around medium performance and low cost 16 or 32 bit μp/μc. 3. Large-scale Highly complex hardware & firmware. Built around 32 or 64 bit RISC μp/μc or PLDs or SoC or multi-core processors. www.maheshelectronics.wordpress.com
Features and architecture considerations Basic elements of an embedded system: www.maheshelectronics.wordpress.com
Features and architecture considerations System core:-Central processing unit This include: Arithmetic logic unit (ALU), which performs computation. Registers needed for the basic operation of the CPU, such as the program counter (PC), stack pointer (SP), and status register (SR). Further registers to hold temporary results. • Instruction decoder and other logic to control the CPU, handle resets, and interrupts, and so on. www.maheshelectronics.wordpress.com
Features and architecture considerations Memory for the program: Non-volatile (read-only memory, ROM), meaning that it retains its contents when power is removed. Memory for data: Known as random-access memory (RAM) and usually volatile. Input and output ports: To provide digital communication with the outside world. Address and data buses: To link these subsystems to transfer data and instructions. Clock: To keep the whole system synchronized. It may be generated internally or obtained from a crystal or external source; modern MCUs offer considerable choice of clocks. www.maheshelectronics.wordpress.com
Features and architecture considerations Common peripherals:- Timers: Most microcontrollers have at least one timer because of the wide range of functions that they provide. They provide a regular “tick” that can be used to schedule tasks in a program. Many programs are awakened periodically by the timer to perform some action—measure the temperature and transmit it to a base station, for example—then go to sleep (enter a low-power mode) until awakened again. This conserves power, which is vital in battery-powered applications. www.maheshelectronics.wordpress.com
Features and architecture considerations Watchdog timer: This is a safety feature, which resets the processor if the program becomes stuck in an infinite loop. Communication interfaces: A wide choice of interfaces is available to exchange information with another IC or system. They include serial peripheral interface (SPI), inter-integrated circuit (I²C or IIC), asynchronous (such as RS-232), universal serial bus (USB), controller area network (CAN), ethernet, and many others. www.maheshelectronics.wordpress.com
Features and architecture considerations Non-volatile memory for data: This is used to store data whose value must be retained when power is removed. Serial numbers for identification and network addresses are two obvious candidates. Analog-to-digital converter: This is very common because so many quantities in the real world vary continuously. www.maheshelectronics.wordpress.com
Features and architecture considerations Digital-to-analog converter: This is much less common, because most analog outputs can be simulated using PWM. An important exception used to be sound, but even here, the use of PWM is growing in what are called class D amplifiers. Real-time clock: These are needed in applications that must track the time of day. Clocks are obvious examples but data loggers are also an important case. www.maheshelectronics.wordpress.com
Features and architecture considerations Monitor, background debugger, and embedded emulator: These are used to download the program into the MCU and communicate with a desktop computer during development. The processor communicates with these peripherals by reading from, and writing to, particular addresses in memory. These memory locations are called special function registers or peripheral registers to distinguish them from ordinary memories, which simply store data, but exactly the same commands are used—no special commands are needed. In practice, microcontrollers spend much of their time handling the peripheral registers. www.maheshelectronics.wordpress.com
Features and architecture considerations RISC Vs CISC : RISC (Reduced Instruction Set Computer)) CISC (Complex Instruction Set Computer) Supports lesser number of instructions. Supports greater number of instructions. Supports few addressing modes for memory access and data transfer instructions. Supports many addressing modes for memory access and data transfer instructions. Single, fixed length instructions Variable length instructions Instructions take fixed amounts of time for execution Instructions take varying amounts of time for execution Instruction pipelining works effectively and increases the execution speed. Instruction pipelining concept is not effectively works as different sizes and different execution times of instructions. Orthogonal instruction set (allows each instruction to operate on any register and use any addressing mode.) Non-orthogonal set (all instructions are not allowed to operate on any register and use any addressing mode. Less silicon usage and decoding logic is not complex. More silicon usage since more additional decoder logic is required to implement the complex instruction decoding. Because of the simple instructions, the design of compiler is easy. Because of large amount of different and complex instructions, the design of compiler is complex. A larger number of registers are available. Limited no. of general purpose registers www.maheshelectronics.wordpress.com
Features and architecture considerations HARVARD ARCHITECTURE Vs VON-NEUMANN ARCHITECTURE : It has separate buses for instruction as well as data fetching. This means that, the data memory and program memory are separated. It shares single common bus for instruction and data fetching. This means that only one set of addresses covers both data memory and program memory. The memory map shows the addresses at which each type of memory is located. www.maheshelectronics.wordpress.com
Easier to pipeline, so high performance can be achieve. Low performance as compared to Harvard architecture It allows simultaneous access to the program and data memories. For instance, the CPU can read an operand from the data memory at the same time as it reads the next instruction from the program memory. First fetches the instruction and then fetches the data. The two separate fetches slows down the controller’s operation. Because several memory cycles are needed to extract a full instruction from memory, this architecture is intrinsically less efficient. Since data memory and program memory are stored physically in different locations, no chances exist for accidental corruption of program memory Accidental corruption of program memory may occur if data memory and program memory are stored physically in the same chip. A problem with the Harvard architecture is that constant data (often lookup tables) must be stored in the program memory because it is nonvolatile. This means that constants cannot be read in the same way as volatile values from the data memory. Special “table read” instructions must therefore be provided or part of the program memory is mapped into data memory The system is simpler and there is no difference between access to constant and variable data. Separate decoding logic is required, because separate buses and control signals are used for accessing data memory and program memory No additional logic is required because, Same bus and control signals are used for accessing for both data memory and program memory. Comparatively high cost Low cost www.maheshelectronics.wordpress.com
Features and architecture considerations MEMORY MAPPED I/O & I/O MAPPED I/O : I/O devices are mapped into the system memory map. i.e Common address space for memory and I/O ports (The I/O ports are viewed as memory locations and are addressed likewise) I/O devices are mapped into a separate address space. i.e., there is separate address space for memory and I/O ports. www.maheshelectronics.wordpress.com
The control signals used for memory operation and I/O operation are same. M/IO = 1 for both Memory and I/O operations Different control signals are used for memory and I/O operations. M/IO =1 for memory operation M/IO =0 for I/O operation All instruction which can access memory can be used to access I/O ports. Less no. of instructions are for I/O access. ( only IN and OUT instructions) The data can be moved from any register to I/O port and vice-versa. The data transfer takes place between Accumulator and I/O port only The arithmetic, logic and bit manipulation instructions which are available for data in memory can also be used for I/O operations. Hence the processor can directly manipulate data from I/O port. No instructions are available for direct manipulation of I/O data. First the processor reads data from I/O port and then manipulates. Large number of I/O devices can be interfaced Less no. of I/O devices can be interfaced Full address space can’t be used for addressing Memory, because some locations are allotted for I/O ports. Full address space can be used for addressing Memory, because I/O locations are separated from memory. The entire address bus must be fully decoded for every device, which increases the cost Less logic is needed to decode a discrete address and therefore less cost www.maheshelectronics.wordpress.com
Features and architecture considerations LITTLE-ENDIAN & BIG-ENDIAN PROCESSORS Endianness specifies the order which the data is stored in the memory by processor operations in a multi byte system. 2000H 2000H 2001H 2001H 2002H 2002H 2003H 2003H Little-endian means lower order data byte is stored in memory at the lowest address and the higher order data byte at the highest address. Big-endian means the higher order data byte is stored in memory at the lowest and the lower order data byte at the highest address. www.maheshelectronics.wordpress.com
. INTRODUCTION TO MSP430 MICROCONTROLLERS: MAIN CHARACTERISTICS OF MSP430 MICROCONTROLLER Flash (or) ROM-based low-power MCUs CPU clock : 8/16 MHz Operating voltage : 1.8–3.6 V Power specification overview, as low as: 0.1 μA RAM retention 0.7 μA real-time clock mode operation 160 - 250 µA/MIPS at active operation Fast wake-up from standby mode in less than 1 µs. Device parameters Flash/ ROM options: 1 KB – 60 KB RAM options: 128 B– 8 KB GPIO options: 14 - 80 pins www.maheshelectronics.wordpress.com
INTRODUCTION TO MSP430 MICROCONTROLLERS: Other integrated peripherals: 10/12/16-bit Analogue-to-Digital Converter (ADC); 12-bit dual Digital-to-Analogue Converter (DAC); Comparator-gated Timers; Watch Dog Timer SPI, I2C, UART Operational Amplifiers (OP Amps) 16×16 multiplier Comparator_A Temp. sensor LCD driver Supply Voltage Supervisor (SVS) Brown out Reset 16 bit RISC CPU: Instructions processing on either bits, bytes or words; Compact core design reduces power consumption and cost; Compiler efficient; 27 core instructions; 7 addressing modes; Extensive vectored-interrupt capability. www.maheshelectronics.wordpress.com
BLOCK DIAGRAM OF MSP430 F2013/ F2003 MICROCONTROLLER www.maheshelectronics.wordpress.com
MSP430 part numbering: www.maheshelectronics.wordpress.com
VARIANTS OF MSP 430 FAMILY – 1XX, 2XX, 3XX, 4XX, 5XX: VARIANT OF FAMILY POWER SPECIFICATIONS DEVICE PARAMETERS OTHER INTEGRATED PERIPHERALS MSP430x1xx 0.1 μA RAM retention 0.7 μA real-time clock mode 200 μA / MIPS active Features fast wake-up from standby mode in less than 6 µs. Flash/ROM options: 1–60 KB RAM options: 128 B– 2 KB GPIO options: 14/22/48 pins ADC options: Slope, 10 & 12-bit SAR 12-bit DAC, up to 2 16-bit timers, WDT, brown-out reset, SVS, USART module (UART, SPI), DMA, 16×16 multiplier, Comparator_A, Temp. sensor MSP430F2xx 0.3 μA standby mode (VLO) 220 μA / MIPS active Feature ultra-fast wake-up from standby mode in less than 1 μs Flash/ROM options: 1 KB–60 KB RAM options: 128 B – 8 KB GPIO options: 10/16/24/32/48 pins ADC options: Slope, 10 & 12-bit SAR, 16 & 24-bit Sigma Delta operational amplifiers, 12-bit DAC, up to 2 16-bit timers, watchdog timer, brown-out reset, SVS, USI module (I²C, SPI), USCI module, DMA, 16×16 multiplier, Comparator_A+, Temperature sensor MSP430x3xx 0.9 μA real-time clock mode 160 μA / MIPS active ROM options: 2–32 KB RAM options: 512 B–1 KB GPIO options: 14/40 pins ADC options: Slope, 14-bit SAR LCD controller, multiplier MSP430x4xx Flash/ROM options: 4 KB– 60 KB RAM options: 256 B – 8 KB GPIO options: 14/32/48/56/68/72/80 pins ADC options: Slope, 10 & 12-bit SAR, 16-bit Sigma Delta 12-bit DAC, Op Amps, RTC, up to two 16-bit timers, watchdog timer, basic timer, brown-out reset, SVS, USART module (UART, SPI), USCI module, LCD Controller, DMA, 16×16 & 32x32 multiplier, Comparator_A, Temp. sensor MSP430x5xx 2.5 μA real-time clock mode 165 μA / MIPS active Features fast wake-up from standby mode in less than 5 µs. Flash options: up to 512 KB RAM options: up to 66 KB ADC options: 10 & 12-bit SAR GPIO options: 29/31/47/48/63/67/74/87 pins High resolution PWM, 5 V I/O's, USB, backup battery switch, up to 4 16-bit timers, watchdog timer, Real-Time Clock, brown-out reset, SVS, USCI module, DMA, 32x32 multiplier, Comp B, temperature sensor MSP430x6xx GPIO options: 74/90 pins USB, LCD, DAC, Comparator_B, DMA, 32x32 multiplier, power management module (BOR, SVS, SVM, LDO), watchdog timer, RTC, Temp sensor www.maheshelectronics.wordpress.com
Memory map of MSP430 www.maheshelectronics.wordpress.com
MSP430 –CPU architecture & registers The cpu features Calculated branching Table processing 27 RISC instructions 7 addressing modes All instructions use all the addressing modes Full register access Single cycle register operations (RISC) Direct memory-to-memory transfers Constant generator provides most used values www.maheshelectronics.wordpress.com
MSP430 –CPU architecture & registers There are 16 registers Contents are 16-bits User has access to all registers 4 registers are special purpose Note bus structure MDB – Memory Data Bus MAB – Memory Address Bus Also have 2 internal bussed to deliver 2 operand to ALU Diagram is called the datapath of the processor www.maheshelectronics.wordpress.com
MSP430 –CPU architecture & registers R4 thru R15 Registers are indistinguishable Can be used as Data Registers Address Registers Index values Can be accessed with byte or word instructions There is Register-Byte operation and Byte-Register operation – covered later www.maheshelectronics.wordpress.com
MSP430 –CPU architecture & registers R0: Program Counter (PC) : The 16-bit Program Counter (PC/R0) points to the next instruction to be fetched from memory and executed by the CPU. The Program counter is incremented by the number of bytes used by the instruction (2, 4, or 6 bytes, always even). www.maheshelectronics.wordpress.com
MSP430 –CPU architecture & registers R1: Stack Pointer (SP) The stack memory is a memory block where the data is stored in LIFO manner. The Stack Pointer (SP/R1) holds the address of the stack-top. In the MSP430, as in many other processors, the stack is allocated at the top of the RAM and grows down towards low addresses. www.maheshelectronics.wordpress.com
MSP430 –CPU architecture & registers Operation of the Stack : The operation of the stack is illustrated in the following figure. The specific addresses are for MSO430F2013 with 128 Bytes of RAM are from 0x0200 to 0x027F. Hence, Before the execution, the initially the value of SP = 0x0280 www.maheshelectronics.wordpress.com
MSP430 –CPU architecture & registers www.maheshelectronics.wordpress.com
MSP430 –CPU architecture & registers R2: Status Register (SR) The Status Register (SR/R2) stores the status bits and control bits. C : Carry Flag Z : Zero Flag N : Negative Flag V: Signed overflow flag www.maheshelectronics.wordpress.com
MSP430 –CPU architecture & registers Enable Interrupts :: Setting the general interrupt enable (GIE) bit enables maskable interrupts. Clearing the bit disables all maskable interrupts. There are also nonmaskable interrupts, which cannot be disabled with GIE. www.maheshelectronics.wordpress.com
MSP430 –CPU architecture & registers Control of Low-Power Modes : SCG1 (System clock generator 1) : When set, turns off the SMCLK. SCG0 (System clock generator 0) : When set, turns off the DCO dc generator, if DCO-CLK is not used for MCLK or SMCLK. OSCOFF (Oscillator OFF ) : When set, turns off the LF XT1 crystal oscillator, if LFXT1-CLK is not used for MCLK or SMCLK. CPUOFF : When set, turns off the CPU. www.maheshelectronics.wordpress.com
MSP430 –CPU architecture & registers R2/R3: Constant Generator Registers (CG1/CG2) Depending of the source-register addressing modes (As) value, six commonly used constants can be generated without a code word or code memory access to retrieve them. The constants below are chosen based on the bit (As) of the instruction that selects the addressing mode. Register Addressing mode Constant R2 10 +4 11 +8 R3 00 01 +1 +2 -1 (FFFF) www.maheshelectronics.wordpress.com
MSP430 –Addressing modes MSP430 addressing modes Addressing mode – the way in which the operand(s) of an instruction are accessed, i.e., the effective addresses are calculated. 7 modes supported Register Mode – (Rn) – operands are in registers Immediate Mode – #N – The operand is part of the instruction Instructions have format OPCODE #OPERAND Absolute Mode – &ADDR – The address of the operand is given by the word following the opcode Instructions have format OPCODE &ADDRESS www.maheshelectronics.wordpress.com
MSP430 –Addressing modes Remainder of addressing mode Indexed Mode – X(Rn) – (Rn+X) points to (is the address of) the operand. The value X is the next word in the instruction stream after the OPCODE. Symbolic Mode – ADDR – (PC+X) points to the operand. X is the next word. Indirect Register Mode - @Rn – Rn is used as a pointer to the operand. Indirect Autoincrement - @Rn+ - Rn is used as a pointer to the operand. After access Rn is incremented by 1 for .B instructions and by 2 for .W instructions www.maheshelectronics.wordpress.com
INSTRUCTION FORMATS OF MSP430 : Each instruction has 2- parts: The task to be performed – called as Operation code (Opcode) The data to be operated on – called as Operand. Instruction format: There are three core-instruction formats: Dual-operand Single-operand Jump OPCODE OPERAND www.maheshelectronics.wordpress.com
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INSTRUCTION SET OF MSP430 The instructions can be classified as follows: Movement Instructions (Data Transfer) Arithmetic and Logic Instructions Shift and Rotate Instructions Control Transfer instructions (Branch/Subroutine/Interrupt) www.maheshelectronics.wordpress.com
Movement Instructions (Data Transfer) Instruction Operation Example 1 mov.w src, dst Copies data from source to destination dst src mov.w R5, R6 R6 R5 2 push.w src Push data onto stack ( first the SP is decremented by 2 and the source content is stored at stacktop) @ --SP = src push.w R5 SP SP-2 @ SP R5 3 pop.w dst Pop data from stack ( first the content of stacktop is moved to destination and SP is incremented by 2) dst = @SP + + push.w R6 R6 @ SP SP SP+2 www.maheshelectronics.wordpress.com
Arithmetic and Logic Instructions Binary Arithmetic Instructions with Two operands Instruction Operation Example 1 add.w src, dst Add the content of source to destination dst dst + src add.w R5, R6 2 addc.w src, dst Add with carry dst dst + (src + C) addc.w R5, R6 3 adc.w dst Add carry bit to the destination dst dst + C adc.w R6 4 sub.w src, dst Subtract the content of source from destination dst dst - src sub.w R5, R6 5 subc.w src, dst Subtract with borrow dst dst –( src + C) subc.w R5, R6 6 sbc.w dst Subtract borrow bit from the destination dst dst – C sbc.w R6 7 cmp.w src,dst Compares source and destination. Performs ( dst – src), but Only flags are changed If dst > src : C=0, Z=0 If dst < src : C=1, Z=0 If dst = src : C=0, Z=1 cmp.w R5,R6 www.maheshelectronics.wordpress.com
Arithmetic Instructions with One operand Instruction Operation Example 1 clr.w dst Clear destination dst 0 clr.w R6 R6 0 2 dec.w dst The content of destination is decremented by 1 dst dst – 1 dec.w R6 R6 R6 - 1 3 decd.w dst Double decrement The content of destination is decremented by 2 dst dst – 2 decd.w R6 R6 R6 – 2 4 inc.w dst The content of destination is inccremented by 1 dst dst + 1 inc.w R6 R6 R6 + 1 5 incd.w dst Double increment The content of destination is inccremented by 2 dst dst + 2 incd.w R6 R6 R6 + 2 6 tst.w dst Test ( compare with zero) Performs ( dst – 0), but Only flags are changed If dst > 0 : C=0, Z=0 If dst < 0 : C=1, Z=0 If dst = 0 : C=0, Z=1 tsd.w R6 www.maheshelectronics.wordpress.com
Decimal Arithmetic & logical Instructions These instructions are used to perform BCD addition Instruction Operation Example 1 dadd.w src, dst Perfroms the decimal addtion of destination and source with carry dst dst + src + C dadd.w R5, R6 R6 R6 + R5+C 2 dadc.w dst Performs the decimal addition of destination and carry. dst dst + C dadc.w R6 R6 R6 + C Logic Instructions with ONE operand Instruction Operation Example 1 inv.w dst Invert destination Performs bit-wise NOT operation (1’s complement) dst ~dst inv.w R6 www.maheshelectronics.wordpress.com
Logic Instructions with Two operands Instruction Operation Example 1 and.w src, dst Performs bit-wise logic AND operation dst dst AND src and.w R5, R6 2 xor.w src, dst Performs bit-wise logic Ex-OR operation dst dst XOR src xor.w R5, R6 3 bit.w src, dst Performs bit-wise Test operation It performs Logic AND operation, But Only flags are affected bit.w R5, R6 4 bis.w src, dst Set bits in destination The source operand and the destination operand are logically ORed. The result is placed into the destination. The source operand is not affected. dst dst OR src bis.w R5, R6 5 bic.w src, dst Clear bits in destination The inverted source operand and the destination operand are logically ANDed. The result is placed into the destination. The source operand is not affected dst dst AND ~src bic.w R5, R6 www.maheshelectronics.wordpress.com
Byte manipulation www.maheshelectronics.wordpress.com Instruction Instruction Operation Example 1 swpb dst Swap upper and lower bytes The high and the low byte of the operand are exchanged dst.15:8 ↔ dst.7:0 swpb R6 2 sxt dst Extend sign of lower byte The sign of the low byte of the operand is extended into the high byte dst. 15:8 dst.7 If dst.7 = 0: high byte = 00 H afterwards If dst.7 = 1: high byte = FF H afterwards sxt R6 www.maheshelectronics.wordpress.com
Operations on Bits in Status Register These instructions are used to set or clear the flags in Status Register. All these instructions are emulated instructions. Instruction Operation Flag affected 1 clrc Clear Carry bit C = 0 2 clrn Clear Negative bit N = 0 3 clrz Clear Zero bit Z = 0 4 setc Set Carry bit C = 1 5 setn Set Negative bit N = 1 6 setz Set Zero bit Z = 1 7 dint Disable General Interrupts GIE = 0 8 eint Enable General Interrupts GIE = 1 www.maheshelectronics.wordpress.com
Shift and Rotate Instructions Description Operation rla dst Arithmetic shift Left rra dst Arithmetic shift Right rlc dst Rotate Left through Carry rrc dst Rotate Right through Carry www.maheshelectronics.wordpress.com
Control Transfer Instructions Instruction Description Operation 1 br src Branch ( go to) PC src 2 call src Call Subroutine SP SP-2 @ SP PC PC src 3 ret Return from Subroutine PC @ SP SP SP+2 4 reti Return from Interrupt SR @ SP 5 nop No operation ( consumes single cycle ) www.maheshelectronics.wordpress.com
JUMP Instructions www.maheshelectronics.wordpress.com 1 jmp label jmp label Unconditional Jump 2 jc / jlo label Jump if carry / Jump if lower Jump if C =1 3 jnc / jhs label Jump if not carry / Jump higher or same Jump if C =0 4 Jz / jeq label Jump if zero / Jump if equal Jump if Z =1 5 Jnz / jne label Jump if not zero / Jump if not equal Jump if Z =0 6 jn label Jumpif negative Jump if N =1 7 jge label Jump if greater or equal (signed values) Jump if (N xor V) =0 8 jl label Jump if less than (signed values) Jump if (N xor V) =1 www.maheshelectronics.wordpress.com
Sample Embedded system on MSP430 www.maheshelectronics.wordpress.com