Test: Memory Organisation of Embedded Systems - Computer Science Engineering (CSE) MCQ

Explanation: There are four data lines in the memory and these different organisations of memory and these different organisations of memory are apparent when upgrading memory and it also determines how many chips are needed.

Explanation: The minimum number of chips is determined by the number of data lines and the width of the data path from the processor. For example, MC6800 family have a 16-bit wide datapath, 16*1 devices, 4*4 or 2*8 devices are needed.

Explanation: Memory model is defined by a range of memory address which is accessible to the program. For example, in C program, the memory address is stored in the pointer.

Explanation: Endianness defines the order of bytes, that is, whether it is big endian or little endian. The former represents the higher order bits and the latter represents the lower order bits.

Explanation: The IBM’s PowerPC uses big endian representation whereas 8086,ARM and Zilog Z80 uses little representation.

Explanation: The RAM is the primary storage which directly communicates with the CPU. ROM is the secondary storage. Disk drives are capable of providing backup storage and the cache memory is a small high-speed memory which increases the speed of the processor.

Explanation: There are two types of memory organisation, linear addressing in which the entire memory is available to the processor of all times as in Motorola 6800 and the other is segmented addressing where the memory space is divided into several segments and the processor is limited to access the program instructions and data which are located in particular segments.

Explanation: The 8086 processor has a 20-bit address bus, hence it can access a memory of 2²⁰-1 M locations.

Explanation: A stack is a memory which is allocated to the program in last-in, first out pattern. Stack pointer contains the memory address of the stack.

Explanation: SIMM is single in-line memory module is a kind of memory module, which contains random access memory used in computers of the early 1980s and 1990s.

Explanation: The use of By 1 organisation is declined because of the wider data path devices. But it is still used in parity bit and were used in SIMM memory.

Explanation: By 1 organisation is replaced with By 4 organisation because of its reduced address bus and complexity.

Explanation: The address bus of the 8086 is 20-bit and the data bus is 16-bit in size. So the physical address can be calculated by shifting the segment register by 4 to left and by adding the address bus to it.

Explanation: The wider memories support 16-bits because it can integrate more number of the interface logic so that the time consumed by the latches and buffers removes the memory access thus allowing the slower parts to be used in wait state free designs.

Explanation: Zig-zag package of memory is a plastic package used for DRAM. The leads of this package are arranged in a zigzag manner.