There is no single instruction in the 8085 that would set bit 3 at address 25H. One way to do this would be...
PUSH F
LDA 25H
ORI 8H
STA 25H
POP F
The PUSH/POP pair could be eliminated if you did not want to save the accumulator and flags.
fetch SHLD opcode bytefetch direct address least significant bytefetch direct address most significant bytewrite L register contents byte to memorywrite H register contents byte to memory
Both little and big endian are still in use today. In big endian the most significant byte is the smallest address stored. In little endian the least significant byte is the smallest address stored.
RST 2 is one example of a one byte call instruction. It points to 0010H.
Least Significant Bit. Least Significant Byte. (Depends on use.)
SJMP is short jump. In this 2-byte instruction the first byte is opcode and second byte is relative address of target location. This can save some byte of memory in many applications where memory space is in short supply where as LJMP (Long Jump) is 3-byte instruction in which 1st byte is opcode and 2nd and 3rd byte represent the 16- bit address of target location.
There are 74 instructions in the 8085 microprocessor.
A two-byte instruction gives the specific function instruction in two bytes, or two words. The first specifies the opcode, which tells the microprocessor what operation will occur. The second specifies the operand, or the data that the operation is done on.
ORG is an assembler directive that sets the address of the next generated instruction or data byte.
32 byte
In 8086 the instruction queue is 6 byte long. This is because even the longest 8086 instruction is 6 byte long. Thus it is possible to prefetch even the longest instruction in the instruction set.
The Instruction Register contains the current instruction being executed. It is an internal, special register, and you can not do anything explicit with it. If you are referring to the Program Counter, that simply contains the address of the next instruction to execute. It is incremented for each opcode and operand byte fetched.
32 byte