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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
What is the basic difference between instruction RET and IRET in 8086 microprocessor?
RET pops the PC off of the stack, while IRET pops both the flags and the PC off of the stack.
How segment register are used?
The segment register in the 80806/8088 microprocessor contains the base address (divided by 16) of a region of memory. Since the register is 16 bits in size, there are 65,536 possible segment base addresses, ranging from 00000H to FFFF0H, in increments of 00010H.
After address translation at the instruction level, the generated 16 bit offset is added to the selected segment register times 16 to generate a physical address between 00000H and FFFFFH. (If the offset and base go past FFFFFH, they wrap around back to 00000H.) Since the offset is also 16 bits in size, and since the overlap is only 4 bits (times 16), then each 64 kb segment overlaps by 16 bytes.
There are four segment registers; CS, DS, ES, and SS, standing for Code Segment, Data Segment, Extra Segment, and Stack Segment.
CS is used for opcode fetches. DS is used for normal data. ES is used for certain string operations as the destination address. SS is used for stack and frame (BP) data.
The segment registers can be implicitly selected by context, or they can be explicitly selected with a segment prefix opcode.
What is an accession register?
An accession register is a record of all items that have been added to a collection. This can include items that have been donated, purchased, or found. The accession register can be used to track the growth of a collection over time, and to ensure that all items in the collection are accounted for. The register can also be used to help plan future acquisitions, and to track the provenance of items in the collection.
How clock signal are generated in 8085 and what is the frequency of the internal clock?
Early microprocessor neded clock input to be given externally, i.e. an extra clock generator chip is necessary. the clock generator chip had two pins between which a crstal or an RC circuit could be connected for the generation of basic frequency desired. however, microprocessor, that were designed after 1978(Intel 8085, M6809, etc.) had the clock generator circuit embedded in the microprocesor chip.
The number of lines on a bus that can hold data, for example, 8, 16, 32, and 64 lines, which can accommodate 8, 16, 32, and 64 bits at a time.
When does a microprocessor encounter the HLT instruction?
It encounters the HLT instruction when there is not an endless loop or other things that are done endlessly.
What is fetching in microprocessor?
1) Fetch is the first of two stages involved in computer processing. The processor operates by processing instructions in what is called the "fetch/execute cycle." The processor fetches (reads from memory) an instruction and then, depending on the instruction, executes it (takes some further action with it, such as shifting bits to the right or left). Then it fetches the next instruction, and so forth.
Compute the square root of n using 8085 microprocessors?
MVI C,01h
MVI E,01h
MVI A,09h
LABEL:
SBB C
JZ LABEL1
INR C
INR C
INR E
JMP LABEL
LABEL1:MOV A,E
HLT
jus change the value of A in the 3rd line according to whtever number u wish to square rrot..haffun!
Where do you register at mushabelly?
i don't know because i cant find it do they even make em' ask your self that though cuz i don't either?
Why you call microprocessor as a microprocessor?
The emitter of a transistor was placed a micrometer distance between two, so it was called a microprocessor. Technology advanced, and the distance was improved to nano meter. Still, they call it micro.
How many interrupts in 8085 microprocessor?
The processor has 5 interrupts. They are presented below in the order of their priority (from lowest to highest):
INTR is maskable 8080A compatible interrupt. When the interrupt occurs the processor fetches from the bus one instruction, usually one of these instructions:
- One of the 8 RST instructions (RST0 - RST7). The processor saves current program counter into stack and branches to memory location N * 8 (where N is a 3-bit number from 0 to 7 supplied with the RST instruction).
- CALL instruction (3 byte instruction). The processor calls the subroutine, address of which is specified in the second and third bytes of the instruction.
RST5.5 is a maskable interrupt. When this interrupt is received the processor saves the contents of the PC register into stack and branches to 002Ch (hexadecimal) address.
RST6.5 is a maskable interrupt. When this interrupt is received the processor saves the contents of the PC register into stack and branches to 0034h (hexadecimal) address.
RST7.5 is a maskable interrupt. When this interrupt is received the processor saves the contents of the PC register into stack and branches to 003Ch (hexadecimal) address.
Trap is a non-maskable interrupt. When this interrupt is received the processor saves the contents of the PC register into stack and branches to 0024h (hexadecimal) address.
All maskable interrupts can be enabled or disabled using EI and DI instructions. RST 5.5, RST6.5 and RST7.5 interrupts can be enabled or disabled individually using SIM instruction.
Difference between direct addressing mode and indirect addressing mode in detail?
Direct addressing mode means the operand address is contained in the instruction. In the 8085, an example is LDA 1234H, which loads the accumulator with the contents of memory location 1234H. In the 8086/8088, an example is MOV AL,[1234H], which accomplishes nearly the same thing.
Indirect addressing mode means the operand address is contained in a register. In the 8085, an example is LDAX B, which loads the accumulator with the contents of the memory location specified in register BC. In the 8086/8088, an example is MOV AL,[BX], which accomplishes nearly the same thing.
A microprocessor has 24 parallel address lines How many memory locations can the processor address?
32 bit address line can access 4GB of memory. As 2^10 -> 1KB; 2^20 -> 2MB; 2^30 -> 1GB and so on.... 32 bit gives (2^30) * (2^2) = 1GB * 4 = 4GB;
What is function of ALE signal?
ALE, or Address Latch Enable, tells hardware logic that the data on the data bus represents address information that should be latched. This is a technique used called multiplexing, and it allows for the pin count on the processor chip to be reduced.
What are the disadvantages of 8085 microprocessor?
It works on 8 bit
lower address lines has to be multiplexed with data lines
Appropriate control signals have to be generated to interface with memory and I/O devices
8 bit processors are slow
Memory is just 64 kb
By Anmol Bhardwaj
SUSCET Tangori Mohali ( India)
Write a program in assembly language to add two 8 bit numbers?
we can do this using two techniques:
here i m assuming that two number which is to be multiplied are given..
say 05H and 04H,
so coz 5*4 = 5+5+5+5 = 20
and 4*5 = 4+4+4+4+4 = 20
use this concept ...
MVI A,05H;
MVI B,04H;
L1:
ADD A;
DCR B;
JNZ : L1;
STA 2004H;
HLTType your answer here...
How multiplixed data and address bus of 8086 can be de-multiplixed?
The 8086 has a 20 bit address bus and a 16 bit data bus. The low order 16 bits of the address bus share the same 16 pins as the data bus. The low order 16 bits of the address are emitted in the first clock cycle of a memory access cycle. External logic is expected to latch that address. Then the bus becomes a data bus. The high order 4 bits of the address bus are handled separately.
The determination of operand size (8 bit vs 16 bit) is made by BHE and A0. If BHE is high, it is a 16 bit operand at an even address. If BHE is low and A0 is low, it is an 8 bit operand at an even address. If BHE is low and A0 is high, it is an 8 bit operand at an odd address.
What is NOP Instruction stands in 8085 microprocessor?
The NOP instruction is a no-operation instruction. It does nothing to the state of the machine, except to use some time. In the case of the 8085, it uses four clock cycles plus however many wait states are need to access the NOP instruction from memory.
How many memory locations be addressed by a microprocessor with 14 address lines?
A microprocessor that uses 24 bit addressing, such as the Intel 80286, can address 224 or 16,777,216 memory locations. The IBM MainFrame, 360/44 or any modern version running in AMODE=24 also has the same capacity.
Why do people interrupt others when they are speaking?
Because its rude. Communication is a street where both cars are trying to pass at the same time, one has to give way so the other can pass
