Question & Answers

1. What are the advantages of micro controller over microprocessor? The overall system cost is low, as the peripherals are integrated in a single chip. The size is very small. The system is easy to troubleshoot and maintain. If required additional RAM, ROM and I/O ports may be interfaced. The system is more reliable. 2.

1. What is meant by DMA data transfer? DMA stands for Direct Memory Access. In order to transfer bulk amount of data between memory and I/O device without the involvement of CPU, this technique is used. 2. What are the modes of operations supported by 8255? Simple  mode Strobed I/O mode Bidirectional mode 3. What is

1. What are the three basic multiprocessor configurations that the 8086 can support? Coprocessor Configuration Closely Coupled Configuration Loosely Coupled Configuration 2. What do you mean by numeric processor? 8087 is the numeric processor or numeric co-processor. It adds arithmetic, trignometric, exponential and logarithmic instructions to 8086/8088 instruction set for all data types. It supports

1. What do you mean by non maskable interrupt? Non-maskable interrupt (NMI) is the highest priority hardware interrupt that triggers on the positive edge. This interrupt cannot be disabled or masked. It is used to save program data or processor status in case of system power failure. 2. List out the segment registers of 8086?

1. How many machines cycles and T-states are needed to execute STA 4200H in 8085 processor? To execute STA 4200H instruction, 4 machine cycles and 13 T-states are needed. Machine Cycles         T-states Opcode fetch                4 Memory Read               3 Memory