What is block transfer in computer?
What is block transfer in computer?
One definition of a block transfer is a transfer of multiple bytes (or words or registers) of data under the control of a single software instruction.
What is block transfer in microprocessor?
The block transfer instruction move multiword structures from a source address to a destination address, or they com pare two multiword structures for equality. They include word block transfers, word block comparisons, byte block transfer, bit block transfer and text block transfer.
Which instruction is used to perform memory block data transfer in terms in assembly language?
MOVSB instruction is used to transfer bytes only from source memory location (MADS) to destination memory location (MAES).
What is DPTR in 8051?
The Data Pointer (DPTR) is the 8051’s only user-accessible 16-bit (2-byte) register. It is used by the 8051 to access external memory using the address indicated by DPTR. DPTR is the only 16-bit register available and is often used to store 2-byte values.
What are instructions used in block transfer?
Four of the instructions are block transfer instructions which allow the contents of one block of memory bytes to be transferred to another block of memory; the other four instructions are block search instructions which allow a block of memory bytes to be searched for one of the bytes containing a specified value.
How large a data block can be transferred?
Maximum number that can be stored in 16 bits is 216 – 1 = 65535 = 64K (approx.) So, up to 64K bytes of data can be transferred by the DMA controller at a time.
What are data transfer instructions give an example?
Data transfer instructions in 8085 microprocessor
| OPCODE | OPERAND | EXAMPLE |
|---|---|---|
| PUSH | r.p. | PUSH H |
| POP | r.p. | POP H |
| IN | 8-bit port address | IN 15 |
| OUT | 8-bit port address | OUT 15 |
What are the instructions used for block transfer in this program?
MOV is used to transfer the data from memory to accumulator (1 Byte) LXI is used to load register pair immediately using 16-bit address (3 Byte instruction) MVI is used to move data immediately into any of registers (2 Byte) STAX is used to store accumulator into register pair indirectly (3 Byte instruction)
Why stack pointer is 8-bit in 8051?
Why does the stack pointer holds only 8 bit address in 8051 and whereas the program counter holds the 16 bit address? that is the way it was designed. It has only 128 bytes of RAM, so an 8-bit stack pointer is enough. Using external RAM is possible, but requires a special instruction (MOVX).
How are stacks accessed in 8051?
How Stacks are Accessed. As the stack is a section of a RAM, there are registers inside the CPU to point to it. The register used to access the stack is known as the stack pointer register. The stack pointer in the 8051 is 8-bits wide, and it can take a value of 00 to FFH.
How can you avoid CPU involvement in transferring data to device?
This situation can very well be avoided by using an interrupt driven method for data transfer. By using interrupt facility and special commands to inform the interface to issue an interrupt request signal whenever data is available from any device. In the meantime the CPU can proceed for any other program execution.
Which memory is faster than primary memory?
Cache memory is faster than main memory. It consumes less access time as compared to main memory. It stores the program that can be executed within a short period of time. It stores data for temporary use.