FLASH & CACHE MEMORY, SECONDARY MEMORY

FLASH MEMORY

Flash memory is a type of non-volatile memory that can be altered easily by the end user. Flash memory is a feature of many new I/O and storage devices. The intelligence of these devices can be upgraded by simply downloading new software from a vendor-supplied disk to flash memory. Upgrades to early inptu/output and storage devices required the user to replace the old circuit board or chip with a new one. The emergence of flash memory has eliminated this time consuming and constly method of upgrade. Look for non-volatile flash memory to play an increasing role in computer technology as its improvements continue to close the gap between the speed and flexibility of CMOS RAM.

CASHE MEMORY

Cashe Memory Proramms and data are loaded to RAM from secondary storage because the time required to access a programme instruction or piece of datum from RAM is significantly less than from secondary storage. Thousands of instructions or pieces of data can be accessed from RAM in the time it would take to access a single piece of datum from disk storage RAM is essentially a high speed holding area from data and programms. Infact, nothing really happens in a computer system until the programme instructions and data are moved from RAM to the processor. This transfer of instructions and data to the processor can be time consuming, even at microsecond speeds. To facilitate an even faster transfer of instructions and data to the processor, some processors are designed with cache memory. Cache memory is used by computer designers to increase computer system throughout. Throughout refers to the rate at which work can be performed by a computer system.

Like RAM, cache is a high speed holding area for programme instructions and data. However, cache memory uses a technology that is about 10 times faster than RAM and about 100 times more expensive. With only a fraction of the capacity of RAM, cache memory holds only those instructions and data that are likely to be needed next by the processor.

SECONDARY MEMORY

Secondary memory, or Secondary storage is memory also referred as backing storage is used to supplement the capacity of main storage. This memory stores a bulk of information. It is also called auxiliary storage or mass storage. The information stored in this memory is used by the CPU by first bringing it to main memory. Examples of auxiliary memory are magnetic disks, magnetic tape and mass cartridge systems. Auxiliary storage is of two types: Sequential and Direct Access.

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