5:The basic components of computer system 6:ARM
TM
7:DSP Processor Fundamentals 8:VLSI Architectures
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The main memory is the central storage unit in a computer system.
It is a relatively large and fast memory used to store programs and data
during the computer operation. The principal technology used for the main
memory is based on semiconductor integrated circuit. Integrated circuit
RAM (Read Random Memory) chip is available in two possible operation
modes, static and dynamic. The static RAM consists essentially of inter-
nal flip-flops that store the binary information. The stored information
remains valid as long as power is applied to the unit. The dynamic RAM
stores the binary information in the form of electric charge that is applied
to the capacitor. The capacitor is provided inside the chip by MOS transis-
tor. The stored charge on the capacitor tends to discharge with time and
refreshing the dynamic memory must periodically recharge the capacitor.
The dynamic RAM offers reduced power consumption and large storage
capacity in a single memory chip. The static RAM is easier to use and has
shorter read or write cycles.