Page 25 - Computer Class 07

SRAM

It is used primarily to create CPU’s speed-sensitive
cache. Static Random Access Memory (SRAM) uses

multiple transistors for each memory cell. It does

not have a capacitor in each cell.

ROM SRAM

ROM stands for Read Only Memory . It is built-in computer memory. It is a type of
non-volatile memory that is preserved when the computer is powered off. When

ROMs are manufactured, a chip containing its contents is “burned in” and can’t be
modified. These chips contain what’s known as “bootstrap” data and the power on
selftest (POST) diagnostics the computer uses to start up prior to loading the operating
system.

Following are some different types of memory.

EPROM

Erasable Programmable Read Only Memory (EPROM) can

be erased with the help of ultraviolet light and rewritten
many times. These chips are configured by the EPROM
programmer, providing the voltage at the specified levels.
The floating gate is linked to the row through the control

gate. The cell has a value of 1 till the link remains
established. A process known as Fowler-Nordheim
tunneling is performed to change the value to zero. EPROM

PROM

Programmable Read Only Memory (PROM) is memory chip
on which data can be written only once. Once a program
has been written onto a PROM, it remains there forever.

Unlike main memory, PROMs retain their contents when the
computer is turned off.

PROM

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