BINARYUPDATES.COM EMBEDDED SYSTEMS TRAINING
In which type of registers, logic calculations are done?
Accumulator is register in which Arithmetic and Logic calculations are done
Why Crystal is a preferred clock source?
Crystal has high stability, large quality factor and its frequency does not drift with aging. That’s reason crystal is used as a clock source most of times.
What is program counter?
Program counter hold the address of either the first byte of the next instruction to be fetched for execution or the address of the next byte of a multi byte instruction, which has not been completely fetched. In both cases it gets incremented automatically one by one as the instruction bytes get fetched. Also program register keeps the address of the next instruction.
What is Tri-State logic?
Three logic levels are used and they are high, low, high impedance state. The high and low are normal logic levels. High impedance state is electrical open circuit condition.
What happen when HLT instruction is executed in processor?
The microprocessor enters into Halt-State and buses are tri-stated.
What is Pipelining?
A technique used in advanced microprocessors where microprocessor begins executing a second instruction before first has been completed. That is several instructions are in the pipeline simultaneously each at different processing stage. For example: in 8086 to speed up the executing program, the instructions fetching and execution of instructions are overlapped each other. This is known as pipelining.
What is the need of timing diagram?
The timing diagram provides information regarding the status of various signals, when a machine cycle is executed. The knowledge of timing diagram is essential for system designer to select matched peripheral devices like memories, latches, port’s etc. to form a microprocessor system.
What is Baud Rate?
The baud rate is the rate at which the serial data are transmitted. Baud rate is defined as (The time for a bit cell). In some systems one bit cell has one data bit, then the baud rate and bits/sec are same.
What is UART?
The device which can be programmed to perform synchronous or asynchronous serial communication is called USART (Universal Synchronous Asynchronous Receiver Transmitter)
Define T-State?
T-State is defined as one subdivision of the operation performed in one clock period. These subdivisions are internal states. Synchronized with the system clock, and each T-State is precisely equal to one clock period.
Why interfacing is needed for IO Devices
Generally Io devices are slow devices. Therefore the speed of IO devices does not match with the speed of microprocessor. And so an interface provided between system bus and IO devices.
Which transistor is used in each cell of EPROM?
Floating Gate Avalanche Injection MOS (FAMOS) transistor Is used in each cell of EPROM.
What is difference between CPU Bus & System Bus?
The CPU bus has multiplex lined but the system lines for each signal. (The multiplex CPU lines are de-multiplexed by the CPU interface circuit to form system bus).
What does memory mapping means?
The memory mapping is the process of interfacing memories to microprocessor and allocating address to each memory location.
What is drawback of memory mapped IO?
When IO devices are memory mapped, some of the addresses are allotted to IO devices. And so the full address space can’t be used for addressing memory i.e. physical memory address space will be reduced. Hence memory mapping is useful only for small systems where the memory requirement is less.
What is DMA?
The direct data transfer between IO device and memory is called DMA.
How DMA is initiated?
When the IO device needs a DMA transfer, it will send a DMA request signal to DMA controller. The DMA controller in turn sends a HOLD request, it will drive it’s tri-stated pins to high impedance state at the end of current instruction execution and send an acknowledge signal to DMA controller. Now the DMA controller will perform DMA transfer.
What is linking & relocation?
A linker is a program used to join together several project files into one large object file. The linker produces a link file which contains binary codes for all the combined modules. It’s also produces a link map which contains the address information about the link files. The linker does not assign absolute addresses but only relative address starting from zero, so the programs are relocatable & can be put anywhere in memory to be run.
What are the advantages of modular programming?
Modular programming can be used to break up a large program into manageable units, or to create code that can be easily re-used. Reduce problem to smaller, simpler humanly comprehensible problems.
Define Two-Pass Assembler?
A Two-Pass Assembler does two passes over the source file (the second pass can be over a file generated in first pass). In the first pass all it does is looks for label definitions and introduces them in the symbol table. In the second pass after the symbol table is complete, it does the actual assembly by translating the operations and so on.
Define Assembly process?
A Microprocessor executes a collection of machine instructions that tell the processor, what to do is known as assembly process.
What are directives?
Assembler directives are instructions to the assembler concerning the program being assembled.
What do you mean by assembler directives?
There are some instructions in assembly language program which are not a part of processor instruction set. These instructions to assembler, linker and loader. They are referred as assembler directives. The assembler directives enable us to control the way in which a program assembles and lists. They acts during the assembly of program and do not generate any executable machine code i.e. code, data.
What are mnemonics?
Mnemonics are instructions or commands to perform a particular operation given by user to microprocessor e.g. MOV, ADD, and SUB etc.
What is Compiler?
Compiler is used to translate the high-level language program into machine code.
What is meant by cross-compiler?
A program runs on one machine and executes on another is called as cross compiler.
Here is the end of this post. Probably from next post will see more specific questionnaire on Embedded System and Embedded C. I hope you’ll find this post educational.
