M3S2 Flashcards
consists of electronic components that store
instructions waiting to be executed by the processor,
data needed by those instructions, and the results of
processing the data
memory
memory stores three basic categories of items
The operating
system and other
system software
Application
programs
Data being
processed and the
resulting
information
Each location in memory has an
address
Memory size is measured in
kilobytes (KB or K),
megabytes (MB), gigabytes (GB), or terabytes (TB)
The system unit contains two types of memory:
Volatile memory
Nonvolatile memory
Loses its contents when
power is turned off
volatile memory
example of volatile memory
ram
Does not lose contents
when power is removed
Nonvolatile memory
examples of Nonvolatile memory
ROM,
flash memory, and
CMOS
Three basic types of RAM chips exist:
Dynamic RAM
(DRAM)
Static RAM (SRAM)
Magnetoresistive
RAM (MRAM)
is a type of random-access memory that stores each bit of data in
a separate capacitor within an integrated circuit.
Dynamic RAM
can
be either charged or discharged
capacitor
has three different states.
Static RAM
- standby
- reading
- writing
the circuit is idle
standby
the data has been requested
reading
updating the
contents
writing
data in MRAM is not stored as electric charge or current flows, but
by
magnetic storage elements.
Dynamic RAM
- SDRAM
- DDR SDRAM
- DDR2 SDRAM
- DDR3 SDRAM
memory transfer data on both the rising and falling edges of the clock
signal
• DDR SDRAM (Double Data Rate Synchronous Dynamic RAM)
Singe Data rate RAM
• SDRAM
• DDR SDRAM
(Double Data Rate Synchronous Dynamic RAM)
8.5 GT/s; “dual channel mode”; memory installed in pairs
DDR2 SDRAM
Operates at lower voltages; consuming less power
DDR3 SDRAM
• 12.8 GT/s; dual and triple channel modes
• DDR3 SDRAM
