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Intel 8085
Introduced by Intel in 1977, the Intel 8085 is an 8-bit microprocessor that is binary-compatible with Intel 8080. It only requires a +5-volt power supply and has been used as a microcontroller.
1,493 Questions
When ANI F instruction is used in microprocessor?
The ANI F instruction causes the assembler to look in the symbol table for the symbol F, and to build an instruction that ANDs immediate that value with the accumulator. If you meant to say ANI 0FH, that means to clear the high 4 order bits of the accumulator and to retain the low 4 order bits.
What is a register in microcontroller?
Registers are small memory elements of size in few byte or word. Registers can be accessed quickly by the ALU (Arithmetic and Logic Unit) of micro controllers.
Why is trap nonmaskable in 8085 microprocessor?
The TRAP interrupt is nomaskable in the 8085 microprocessor because TRAP is intended to indicate some serious system problem, or a hardware assisted debugger single step facility.
How do you draw timing diagram of ADD M instruction?
I'm assuming that you mean "Add the contents of memory to an accumulator and place the sum back in the accumulator".
First, the address of the memory location needs to be placed on the address bus and the control lines to memory need to be driven in such a way as to tell the memory that a write operation has been requested (usually enabling OE and synchronizing with a clock).
Next (one or more clock cycles later depending on the type of memory being used), the data is returned from the memory. It must then be routed to the ALU.
The value in the accumulator must also be moved to the ALU and can be performed in either the first or second CPU cycle, depending on the internal architecture of the CPU. It is probably safest to do this in the first cycle.
Next the ALU must perform the addition instruction (third CPU cycle).
Finally, in the fourth cycle, the result can be moved from the ALU back to the accumulator.
How do you use 8 bit register as 16 bit register?
8 bit registers cannot be used as 16 bit registers. The reverse works, however, as the 16 bit general purpose registers of the 8086 and 8088 can be used as pairs of 8 bit registers. AX is divided into AH (high 8 bits) and AL (low 8 bits), and BX, CX, and DX are similarly divided.
Operations on 16 bit and operations on 8 bit registers are similar. So you can do add ah, bl, just as you could do add ax, bx.
What is READ pin in 8085 in microprocessor?
The read pin (RD/) on the 8085 is pin 32. It indicates that external logic should drive the data bus with data during a read cycle. It goes true (low) one half clock cycle after the falling edge of ALE, at which point external hardware should have strobed the content of the data bus to record the low order address bus value. At the same time, READY (pin 35) is sampled. If READY is found to be false (low), the processor holds the state of all lines for one clock cycle and then repeats. One clock cycle after READY is true, the processor samples the data bus. One half clock cycle later, RD/ is set false (high), ending the read cycle, at which point the external hardware must stop driving the data bus. One half clock cycle later, a new machine cycle starts with the rising edge of ALE.
A brownout is a complete power failure?
A brownout refers to the drop in voltage in an electrical power supply system. A blackout, on the other hand, is the complete loss of electric power in an area.
Hyper-threading is using one processor but logically dividing it into two so that it gives the user the benefit of two processors with only using the resources equivalent to almost one. This is achieved by sharing, partitioning and duplicating the various resources almost into two processors. Used by the latest Pentium processors, which are HT enabled, in layman's terms, it allows you to use more than two applications at the same time without slowing down processing speed.
Multi-threading is when various processes are time sliced such that it gives the user the impression that all the programs are being run at the same time. This is what happens on your computer regularly.
Super-threading allows threads from different processes to be executed at the same time unlike Multi-threading where every process has a time slot during which, thread from only one process will be executed. But every time, if for example, there are four instructions issued to the processor. They will all be from the same process. Hyper-threading takes it a step further. It allows threads from different processes to be issued at the same time, in turn, utilizing the waste cycles of the processor. You can go to any Intel site for further info on this.
Another answer:
Super-threading is a multithreading approach that weaves together the execution of different threads on a single processor without truly executing them at the same time. This qualifies it as time-sliced or temporal multithreading rather than simultaneous multithreading. It is motivated by the observation that the processor is occasionally left idle while executing an instruction from one thread. Super-threading seeks to make use of unused processor cycles by applying them to the execution of an instruction from another thread.
Multithreading computers have hardware support to efficiently execute multiple threads. These are distinguished from multiprocessing systems (such as multi-core systems) in that the threads have to share the resources of single core: the computing units, the CPU caches and the translation lookaside buffer (TLB). Where multiprocessing systems include multiple complete processing units, multithreading aims to increase utilization of a single core by leveraging thread-level as well as instruction-level parallelism. As the two techniques are complementary, they are sometimes combined in systems with multiple multithreading CPUs and in CPUs with multiple multithreading cores.
Hyper-threading is Intel's trademarked term for its simultaneous multithreading implementation in their Pentium 4, Atom, Core i7, and certain Xeon CPUs. Hyper-threading (officially termed Hyper-Threading Technology or HTT) is an Intel-proprietary technology used to improve parallelization of computations (doing multiple tasks at once) performed on PC microprocessors. A processor with hyper-threading enabled is treated by the operating system as two processors instead of one. This means that only one processor is physically present but the operating system sees two virtual processors, and shares the workload between them. Hyper-threading requires both operating system and CPU support for efficient usage; conventional multiprocessor support is not enough, and may actually decrease performance if the Operating System is not sufficiently aware of the distinction between a physical core and a HTT-enabled core. For example, Intel does not recommend that hyper-threading be enabled under Windows 2000, even though the operating system supports multiple CPUs (but is not HTT-aware).
A number line is a line of which numbers are ordered on. Usually from 1 to 100.
What is function of IO-M in 8085?
I/O and memory operations are differentiated by this status signal. When it is HIGH, I/O operation takes place and when LOW, memory operation takes place. This signal is combined with read/write in order yo generate I/O and memory control signals.
Which flags are checked after instruction JNC and JNZ?
JNC is Jump No-Carry, so the carry flag is checked. JNZ is Jump No-Zero, so the zero flag is checked.
What is the history of segments registers?
Minicomputers during the late 1970s were running up against the 16-bit 64-KB address limit, as memory had become cheaper. Some minicomputers like the PDP-11 used complex bank-switching schemes, or, in the case of Digital's VAX, redesigned much more expensive processors which could directly handle 32-bit addressing and data. The original 8086, developed from the simple 8080microprocessor and primarily aiming at very small and inexpensive computers and other specialized devices, instead adopted simple segment registers which increased the memory address width by only 4 bits. By multiplying a 64-KB address by 16, the 20-bit address could address a total of one megabyte (1,048,576 bytes) which was quite a large amount for a small computer at the time. The concept of segment registers was not new to many mainframes which used segment registers to quickly swap to different tasks. In practice, on the x86 it was (is) a much-criticized implementation which greatly complicated many common programming tasks and compilers. However, the architecture soon allowed linear 32-bit addressing (starting with the 80386 in late 1985) but major actors (such as Microsoft) took many years to convert their 16-bit based systems. The 80386 (and 80486) was therefore largely used as a fast (but still 16-bit based) 8086 for many years.
Data and/or code could be managed within "near" 16-bit segments within this 1 MB address space, or a compiler could operate in a "far" mode using 32-bit segment:offset pairs reaching (only) 1 MB. While that would also prove to be quite limiting by the mid-1980s, it was working for the emerging PC market, and made it very simple to translate software from the older 8008, 8080, 8085, andZ80 to the newer processor. In 1985, the 16-bit segment addressing model was effectively factored out by the introduction of 32-bit offset registers, in the 386 design.
In real mode, segmentation is achieved by shifting the segment address left by 4 bits and adding an offset in order to receive a final 20-bit address. For example, if DS is A000h and SI is 5677h, DS:SI will point at the absolute address DS × 10h + SI = A5677h. Thus the total address space in real mode is 220 bytes, or 1 MB, quite an impressive figure for 1978. All memory addresses consist of both a segment and offset; every type of access (code, data, or stack) has a default segment register associated with it (for data the register is usually DS, for code it is CS, and for stack it is SS). For data accesses, the segment register can be explicitly specified (using a segment override prefix) to use any of the four segment registers.
In this scheme, two different segment/offset pairs can point at a single absolute location. Thus, if DS is A111h and SI is 4567h, DS:SI will point at the same A5677h as above. This scheme makes it impossible to use more than four segments at once. CS and SS are vital for the correct functioning of the program, so that only DS and ES can be used to point to data segments outside the program (or, more precisely, outside the currently-executing segment of the program) or the stack.
In protected mode, a segment register no longer contains the physical address of the beginning of a segment, but contain a "selector" that points to a system-level structure called a segment descriptor. A segment descriptor contains the physical address of the beginning of the segment, the length of the segment, and access permissions to that segment. The offset is checked against the length of the segment, with offsets referring to locations outside the segment causing an exception. Offsets referring to locations inside the segment are combined with the physical address of the beginning of the segment to get the physical address corresponding to that offset.
The segmented nature can make programming and compiler design difficult because the use of near and far pointers affects performance.- yogeshwar Nair
How many instructions are there in each clock cycle?
If this is a homework assignment, you really should try to answer it on your own first, otherwise the value of the reinforcement of the lesson due to actually doing the assignment will be lost on you.
The number of clock cycles per instruction in the 8085 varies between 4 and 18, so the number of instructions per clock cycle varies between 0.25 and 0.056. This does not include wait states.
There are 2 types interrupts in 8085 such as:
1)hardware interrupt
2)software interrupt
How do you build 8085 using vhdl?
VHDL is a hardware description language. It describes the functionality of a hardware as a program. If we know the architecture of 8085, the same can be implemented or coded using VHDL.
What is the simple program for 8bit addition using 8085 microprocessor?
Suppose you want to add 11 and 12.instruction are :
mvi a,11h
mvi b ,12h
mov d,b
add b
Describe RST 5.5 interrupts in 8085 microprocessor with examples?
RST 5.5 is level triggered interrupt & maskable also. it can be masked by using SIM intrruction.
Vector address of the RST 5.5 interrupt is 002Ch
What is the role of microprocessor?
Microprocessor are widely used in this generation for performing any type of electrical signal processing task. because of it's feaatures. Some of them are described here-
1> very fast processing
2> programmable
3> easily interface between peripherals
4>less extra hardware.
5> reliable
6>economical.
7>compact and portable.
Explain the different types of Computer Architecture?
The computer architecture is concerned with how the CPU acts and uses the computer memory.
How were microprocessors for automobiles developed?
* ECU- controls engine functions * Airbag Module- controls airbag deployment * Body Controller- controls interior lights, door locks, windows, seats, etc * Driver's Door Module- communicates commands from switches on drivers door to the body controller * Cruise Control Module- Regulates speed while in cruise control * Climate Control Module- Monitors interior temperature and controls the heating and cooling systems * Transmission Controller- controls automatic transmission * ABS Module- controls anti-lock brakes and may handle the traction-control and stability-control systems * Power Distribution Box Module- controls relays in the power distribution box * Instrument Panel- Controls gauges, and indicator lights using data from the communications bus
The different types of FLAGS register?
There are a huge number of different FLAG registers. The most common are zero flag (Z), carry flag (C), sign flag/ negative flag (S/N), and overflow flag (V/O/W). Each flag contains different information about the state of the processor.
What is ax or accumulator register?
Accumulator is a general purpose register.it is a 8 bit register in 8085. it stores the temporary results of a current operation doing by 8085.it is also called 'A' register
