Advanced Computer Architecture -
Exam 2
*Main memory* is made of what type of RAM? - Answer-DRAM
How do DRAM cells store data? - Answer-As charge on capacitors -- the presence of a charge in an upper
range is interpreted as a 1, and the presence of a charge in a lower range is interpreted as a 0
Which type of RAM requires periodic refresh? - Answer-DRAM
Which type of RAM has a higher access time? - Answer-DRAM
A *cache* is made of what type of RAM? - Answer-SRAM
How do SRAM cells store data? - Answer-Through traditional flip flop logic gates
True or false: SRAM will hold its data as long as power is supplied to it - Answer-True
Which has a greater cost per bit: SRAM or DRAM? - Answer-SRAM
True or false: SRAM cells must be refreshed periodically - Answer-False
Looking at the DRAM cell diagram:
, 1. How do reads work?
2. How do writes work? - Answer-1. When the cell is being read from, the address line is activated,
closing the transistor and allowing current to flow. The charge stored on the capacitor is fed out onto
the bit line, where it is read by a sense amplifier.
2. When the cell is being written to, the address line is activated, closing the transistor and allowing
current to flow. A voltage signal will be applied to the bit line: a high voltage signal is 1, a low voltage
signal is 0. This voltage signal is transferred into and stored in the capacitor.
Looking at the SRAM cell diagram:
1. How do reads work?
2. How do writes work? - Answer-Four transistors are cross-connected in an arrangement that produces
a stable logic state. When an address is sent on the address line, two extra transistors open up to allow a
read or write operation.
1. The bit value is read from the bit line.
2. The desired bit value is applied to the bit line and its complement is applied to the bit complement
line, forcing the four cross-connected transistors into a stable logic state representing the desired value.
What is *read-only memory (ROM)*? - Answer-A storage device that contains a permanent pattern of
data that cannot be added to or modified
Is ROM volatile? - Answer-No
When is data written into ROM? - Answer-At the time of the original chip fabrication
Exam 2
*Main memory* is made of what type of RAM? - Answer-DRAM
How do DRAM cells store data? - Answer-As charge on capacitors -- the presence of a charge in an upper
range is interpreted as a 1, and the presence of a charge in a lower range is interpreted as a 0
Which type of RAM requires periodic refresh? - Answer-DRAM
Which type of RAM has a higher access time? - Answer-DRAM
A *cache* is made of what type of RAM? - Answer-SRAM
How do SRAM cells store data? - Answer-Through traditional flip flop logic gates
True or false: SRAM will hold its data as long as power is supplied to it - Answer-True
Which has a greater cost per bit: SRAM or DRAM? - Answer-SRAM
True or false: SRAM cells must be refreshed periodically - Answer-False
Looking at the DRAM cell diagram:
, 1. How do reads work?
2. How do writes work? - Answer-1. When the cell is being read from, the address line is activated,
closing the transistor and allowing current to flow. The charge stored on the capacitor is fed out onto
the bit line, where it is read by a sense amplifier.
2. When the cell is being written to, the address line is activated, closing the transistor and allowing
current to flow. A voltage signal will be applied to the bit line: a high voltage signal is 1, a low voltage
signal is 0. This voltage signal is transferred into and stored in the capacitor.
Looking at the SRAM cell diagram:
1. How do reads work?
2. How do writes work? - Answer-Four transistors are cross-connected in an arrangement that produces
a stable logic state. When an address is sent on the address line, two extra transistors open up to allow a
read or write operation.
1. The bit value is read from the bit line.
2. The desired bit value is applied to the bit line and its complement is applied to the bit complement
line, forcing the four cross-connected transistors into a stable logic state representing the desired value.
What is *read-only memory (ROM)*? - Answer-A storage device that contains a permanent pattern of
data that cannot be added to or modified
Is ROM volatile? - Answer-No
When is data written into ROM? - Answer-At the time of the original chip fabrication
