Anna University COMPUTER ORGANIZATION AND ARCHITECTURE Two marks unit 4
MEMORY SYSTEM
1. What is the maximum size of the memory that can be used in a 16-bit computer and 32 bit computer?
The maximum size of the memory that can be used in a 16-bit computer is 216=64K memory locations.
The maximum size of the memory that can be used in a 32-bit computer is
232 =4G memory locations.
2. Define memory access time?
The time required to access one word is called the memory access time. Or it is the time that elapses between the initiation of an operation and the completion of that operation.
3. Define memory cycle time?
It is the minimum time delay required between the initiation of two successive memory operations. Eg. The time between two successive read operations.
4. When is a memory unit called as RAM?
A memory unit is called as RAM if any location can be accessed for a read or write operation in some fixed amount of time that is independent of the location’s address.
5. What is MMU?
MMU is the Memory Management Unit. It is a special memory control circuit used for implementing the mapping of the virtual address space onto the physical memory.
6. Define memory cell?
A memory cell is capable of storing one bit of information. It is usually organized in the form of an array.
7. What is a word line?
In a memory cell, all the cells of a row are connected to a common line called as word line.
8. Define static memories?
Memories that consists of circuits capable of retaining their state as long as power
is applied is called Static memories.
9.What are the Characteristics of semiconductor RAM memories?
10.Why SRAMs are said to be volatile?
Because their contents are lost when power is interrupted. So SRAMs are said to be volatile.
11.What are the Characteristics of SRAMs?
12.What are the Characteristics of DRAMs?
13.Define Refresh Circuit?
It is a circuit which ensures that the contents of a DRAM are maintained when each row of cells are accessed periodically.
14.Define Memory Latency?
It is used to refer to the amount of time it takes to transfer a word of data to or from the memory.
15.what are asynchronous DRAMs?
In asynchronous DRAMs, the timing of the memory device is controlled asynchronously. A specialised memory controller circuit provides the necessary control signals RAS and CAS that govern the timing.The processor must take into account the delay in the response of the memory. such memories are asynchronous DRAMs .
16.what are synchronous DRAMs?
Synchronous DRAMs are those whose operation is directly synchronized with a clock signal.
17.Define Bandwidth?
When transferring blocks of data, it is of interest to know how much time is needed to transfer an entire block. since blocks can be variable in size it is useful to define a performance measure in terms of number of bits or bytes that can be transferred in one second. This measure is often referred to as the memory bandwidth.
18. What is double data rate SDRAMs?
Double data rates SDRAMs are those which can transfer data on both edges of the clock and their bandwidth is essentially doubled for long burst transfers.
19.What is motherboard?
Mother Board is a main system printed circuit board which contains the processor. It will occupy an unacceptably large amount of space on the board.
20.What are SIMMs and DIMMs?
SIMMs are Single In-line Memory Modules. DIMMs are Dual In-line Memory Modules. Such modules are an assembly of several memory chips on a separate small board that plugs vertically into a single socket on the motherboard.
21.What is memory Controller?
A memory controller is a circuit which is interposed between the processor and the dynamic memory. It is used for performing multiplexing of address bits.It provides RAS-CAS timing. It also sends R/W and CS signals to the memory. When used with DRAM chips , which do not have self refreshing capability , the memory controller has to
provide all the information needed to control the refreshing process.
22. Differentiate static RAM and dynamic RAM?
23. What is Ram Bus technology?
The key feature of Ram bus technology is a fast signaling method used to transfer information between chips. Instead of using signals that have voltage levels of either 0 or V supply to represent the logic values, the signals consist of much smaller voltage swings around a reference voltage, vref. Small voltage swings make it possible to have short transition times, which allows for a high speed of transmission.
24.What are RIMMs?
RDRAM chips can be assembled in to larger modules called RIMMs. It can hold upto 16 RDRAMs.
25. What are RDRAMs?
RDRAMs are Rambus DRAMs. Rambus requires specially designed memory chips. These chips use cell arrays based on the standard DRAM technology. Multiple banks of cell arrays are used to access more than one word at atime. Circuitry needed to interface to the Rambus channel is included on the chip. Such chips are known as RDRAMs.
26.What are the special features of Direct RDRAMs?
27. Define ROM?
It is a non-volatile memory. It involves only reading of stored data.
28.What are the features of PROM?
29.Why EPROM chips are mounted in packages that have transparent window?
Since the erasure requires dissipating the charges trapped in the transistors of memory cells. This can be done by exposing the chip to UV light .
30.What are the disadvantages of EPROM?
The chip must be physically removed from the circuit for reprogramming and its entire contents are erased by the ultraviolet light.
31.What are the advantages and disadvantages of using EEPROM?
The advantages are that EEPROMs do not have to be removed for erasure.Also it is possible to erase the cell contents selectively. The only disadvantage is that different voltages are needed for erasing, writing and reading the stored data.
32.What is cache memory?
It is a small, fast memory that is inserted between the larger, slower main memory and the processor. It reduces the memory access time.
33. Differentiate flash devices and EEPROM devices.
34.Define flash memory?
It is an approach similar to EEPROM technology. A flash cell is based on a single transistor controlled by trapped charge just like an EEPROM cell.
35. What is locality of reference?
Analysis of programs shows that many instructions in localized areas of the program are executed repeatedly during some time period., and the remainder of the program is accessed relatively infrequently. This is referred to as locality of reference. This property leads to the effectiveness of cache mechanism.
36. What are the two aspects of locality of reference?. Define them.
Two aspects of locality of reference are temporal aspect and spatial aspect. Temporal aspect is that a recently executed instruction is likely to be executed again very
soon. The spatial aspect is that instructions in close proximity to a recently executed instruction are also to be executed soon.
37. Define cache line.
Cache block is used to refer to a set of contiguous address locations of some size. Cache block is also referred to as cache line.
38.What are the two ways in which the system using cache can proceed for a write
operation?
Ø Write through protocol technique.
Ø Write-back or copy back protocol technique.
39. What is write through protocol?
For a write operation using write through protocol during write hit: the cache location and the main memory location are updated simultaneously. For a write miss: For a write miss, the information is written directly to the main memory.
40.When does a readmiss occur?
When the addressed word in a read operation is not in the cache, a read miss
occur.
41. What is write-back or copy back protocol?
For a write operation using this protocol during write hit: the technique is to update only the cache location and to mark it as updated with an associated flag bit, often called the dirty or modified bit. The main memory location of the word is updated later, when the block containing this marked word is to be removed from the cache to make room for a new block. For a write miss: the block containing the addressed word is first brought into the cache, and then the desired word in the cache is overwritten with the new information.
42.What is load-through or early restart?
When a read miss occurs for a system with cache the required word may be sent to the processor as soon as it is read from the main memory instead of loading in to the cache. This approach is called load through or early restart and it reduces the processor’s waiting period.
43.What are the mapping technique?
44.What is a hit?
A successful access to data in cache memory is called hit.
45.Define hit rate?
The number of hits stated as a fraction of all attempted access .
46.What are the two ways of constructing a larger module to mount flash chips on a small card?
47.Describe the memory hierarchy?
48.Define miss rate?
It is the number of misses stated as a fraction of attempted accesses.
49.Define miss penalty?
The extra time needed to bring the desired information into the cache.
50.Define access time for magnetic disks?
The sum of seek time and rotational delay is called as access time for disks. Seek time is the time required to move the read/write head to the proper track. Rotational delay or latency is the amount of time that elapses after the head is positioned over the correct track until the starting position of the addressed sector passes under the read/write head.
51.What is phase encoding or Manchestor encoding?
It is one encoding technique for combining clocking information with data. It is a scheme in which changes in magnetization occur for each data bit. It s disadvantage is poor bit-storage density.
52.What is the formula for calculating the average access time experienced by the processor?
tave=hc +(1-h)M
Where
h =Hit rate
M=miss penalty
C=Time to access information in the cache.
53. What is the formula for calculating the average access time experienced by the processor in a system with two levels of caches?
tave =h1c1(1-h1)h2c2+(1-h1)(1-h2)M
where
h1=hit rate in L1 cache
h2=hit rate in L2 cache
C1=Time to access information in the L1 cache.
C2=Time to access information in the L2 cache.
54.What are prefetch instructions?
Prefetch Instructions are those instructions which can be inserted into a program either by the programmer or by the compiler.
55.Define system space?
Management routines are part of the operating system of the computer.It is convenient to assemble the OS routines into a virtual address space.
56.Define user space?
The system space is separated from virtual address space in which the user application programs reside. The letter space is called user space.
57.What are pages?
All programs and data are composed of fixed length units called pages.each consists of blocks of words that occupies contiguous locations in main memory.
58.What is replacement algorithm?
When the cache is full and a memory word that is not in the cache is referenced, the cache control hardware must decide which block should be removed to create space for the new block that contains the reference word .The collection of rules for making this decision constitutes the replacement algorithm.
59.What is dirty or modified bit?
The cache location is updated with an associated flag bit called dirty bit.
60.What is write miss?
During the write operation if the addressed word is not in cache then said to be write miss.
61.What is associative research?
The cost of an associative cache is higher than the cost of a direct mapped cache because of the need to search all 128 tag patterns to determine whether a given block is in the cache. A search of this kind is called an associative search.
62.What is virtual memory?
Techniques that automatically move program and datablocks into the physical main memory when they are required for execution are called as virtual memory.
63.What is virtual address?
The binary address that the processor used for either instruction or data called as virtual address.
64.What is virtual page number?
Each virtual address generated by the processor whether it is for an instruction fetchis interpreted as a virtual page.
65.What is page frame?
An area in the main memory that can hold one page is called as page frame.
66.What is Winchester technology?
The disk and the read/write heads are placed in a sealed air-filtered enclosure called Winchester technology.
67.What is a disk drive?
The electromechanical mechanism that spins the disk and moves the read/write heads called disk drive.
68.What is disk controller?
The electronic circuitry that controls the operation of the system called as disk controller.
69.What is main memory address?
The address of the first main memory location of the block of words involved in the transfer is called as main memory address.
70.What is word count?
The number of words in the block to be transferred.
71.What is Error checking?
It computes the error correcting code (ECC)value for the data read from a given sector and compares it with the corresponding ECC value read from the disk.
72.What is booting?
When the power is turned on the OS has to be loaded into the main memory which takes place as part of a process called booting.To initiate booting a tiny part of main memory is implemented as a nonvolatile ROM.
73.What are the two states of processor?
74.What is lockup-free?
A cache that can support multiple outstanding misses is called lockup-free.
75.Draw the static RAM cell?
PART-B
1. Write notes on semiconductor RAM memories.
2. Write notes on various types of ROMs.
3. What are the various types of cache mapping mechanisms? Explain in detail.
4. Write notes on secondary storage devices.
6. What are the various techniques used to improve the performance of cache. Explain it.
7. Explain with neat diagram the internal organization of bit cells in a memory chip.
Hints: Memory cells are usually organized in the form of an array, in which each cell is capable of storing one bit of information. Each row consists a memory word, and all cells of a row are connected to a common line referred to as word line, which is driven by he address decoder on the chip.
8. Discuss the virtual memory management technique in detail
Hints: The data is to be stored in physical memory locations that have addresses different from those specified by the program. The memory control circuitry translates the address specified by the program into an address that can be used to access the physical memory.
9. What is memory interleaving? Explain with neat diagram.
Hints: The main memory of a computer is structure as a collection of physically separate modules each with its own address buffer register and data buffer register, memory access operations may proceed in more than one module at the same time. Thus the aggregate rate of transmission of words to and from the main memory system can be increased.
10.Write brief notes on Optical Disks
11. Explain in detail Magnetic Hard Disks
12. Write notes on Performance Considerations
• Internal organization of memory chips
• Static memories
• Asynchronous DRAMs
• Synchronous DRAMs
• Structure Of Larger Memories
• Memory System Considerations
• Rambus Memory
2. Write notes on various types of ROMs.
• ROM
• PROM
• EPROM
• EEPROM
• Flash Memory
3. What are the various types of cache mapping mechanisms? Explain in detail.
• Direct mapping
• Associative mapping
• Set Associative mapping
4. Write notes on secondary storage devices.
• Magnetic hard disks
• Floppy disks
• Optical disks
• DVD
• Magnetic tape systems
5. Write notes on Virtual memories.
• Address Translation
• Diagram
• Explanation
6. What are the various techniques used to improve the performance of cache. Explain it.
• Reducing the miss rate
• Reducing the miss penalty
• Reducing the miss rate or miss penalty using parallelism
• Reducing the time to hit in a cache
7. Explain with neat diagram the internal organization of bit cells in a memory chip.
Hints: Memory cells are usually organized in the form of an array, in which each cell is capable of storing one bit of information. Each row consists a memory word, and all cells of a row are connected to a common line referred to as word line, which is driven by he address decoder on the chip.
8. Discuss the virtual memory management technique in detail
Hints: The data is to be stored in physical memory locations that have addresses different from those specified by the program. The memory control circuitry translates the address specified by the program into an address that can be used to access the physical memory.
9. What is memory interleaving? Explain with neat diagram.
Hints: The main memory of a computer is structure as a collection of physically separate modules each with its own address buffer register and data buffer register, memory access operations may proceed in more than one module at the same time. Thus the aggregate rate of transmission of words to and from the main memory system can be increased.
10.Write brief notes on Optical Disks
• CD Technology
• CD-ROM
• CD-Recordables
• CD-Rewritables
• DVD Technology
• DVD-RAM
11. Explain in detail Magnetic Hard Disks
• Organization And Accessing Of Data On A Disk
• Access Time
• Typical Disks
• Data Buffer/Cache
• Disk Controller
• Software And Operating System Implications
• Floppy Disks
• Raid Disk Arrays
• Commodity Disk Considerations
12. Write notes on Performance Considerations
• Interleaving
• Hit Rate And Miss Penalty
• Caches On Processor Chip
• Other Enhancements
UNIT IV
PART-A
MEMORY SYSTEM
1. What is the maximum size of the memory that can be used in a 16-bit computer and 32 bit computer?
The maximum size of the memory that can be used in a 16-bit computer is 216=64K memory locations.
The maximum size of the memory that can be used in a 32-bit computer is
232 =4G memory locations.
2. Define memory access time?
The time required to access one word is called the memory access time. Or it is the time that elapses between the initiation of an operation and the completion of that operation.
3. Define memory cycle time?
It is the minimum time delay required between the initiation of two successive memory operations. Eg. The time between two successive read operations.
4. When is a memory unit called as RAM?
A memory unit is called as RAM if any location can be accessed for a read or write operation in some fixed amount of time that is independent of the location’s address.
5. What is MMU?
MMU is the Memory Management Unit. It is a special memory control circuit used for implementing the mapping of the virtual address space onto the physical memory.
6. Define memory cell?
A memory cell is capable of storing one bit of information. It is usually organized in the form of an array.
7. What is a word line?
In a memory cell, all the cells of a row are connected to a common line called as word line.
8. Define static memories?
Memories that consists of circuits capable of retaining their state as long as power
is applied is called Static memories.
9.What are the Characteristics of semiconductor RAM memories?
- · They are available in a wide range of speeds.
- · Their cycle time range from 100ns to less than 10ns.
- · They replaced the expensive magnetic core memories.
- · They are used for implementing memories.
10.Why SRAMs are said to be volatile?
Because their contents are lost when power is interrupted. So SRAMs are said to be volatile.
11.What are the Characteristics of SRAMs?
- SRAMs are fast.
- They are volatile.
- They are of high cost.
- Less density.
12.What are the Characteristics of DRAMs?
- Low cost.
- High density.
- Refresh circuitry is needed.
13.Define Refresh Circuit?
It is a circuit which ensures that the contents of a DRAM are maintained when each row of cells are accessed periodically.
14.Define Memory Latency?
It is used to refer to the amount of time it takes to transfer a word of data to or from the memory.
15.what are asynchronous DRAMs?
In asynchronous DRAMs, the timing of the memory device is controlled asynchronously. A specialised memory controller circuit provides the necessary control signals RAS and CAS that govern the timing.The processor must take into account the delay in the response of the memory. such memories are asynchronous DRAMs .
16.what are synchronous DRAMs?
Synchronous DRAMs are those whose operation is directly synchronized with a clock signal.
17.Define Bandwidth?
When transferring blocks of data, it is of interest to know how much time is needed to transfer an entire block. since blocks can be variable in size it is useful to define a performance measure in terms of number of bits or bytes that can be transferred in one second. This measure is often referred to as the memory bandwidth.
18. What is double data rate SDRAMs?
Double data rates SDRAMs are those which can transfer data on both edges of the clock and their bandwidth is essentially doubled for long burst transfers.
19.What is motherboard?
Mother Board is a main system printed circuit board which contains the processor. It will occupy an unacceptably large amount of space on the board.
20.What are SIMMs and DIMMs?
SIMMs are Single In-line Memory Modules. DIMMs are Dual In-line Memory Modules. Such modules are an assembly of several memory chips on a separate small board that plugs vertically into a single socket on the motherboard.
21.What is memory Controller?
A memory controller is a circuit which is interposed between the processor and the dynamic memory. It is used for performing multiplexing of address bits.It provides RAS-CAS timing. It also sends R/W and CS signals to the memory. When used with DRAM chips , which do not have self refreshing capability , the memory controller has to
provide all the information needed to control the refreshing process.
22. Differentiate static RAM and dynamic RAM?
| Static RAM | Dynamic RAM |
| They are fast | They are slow |
| They are very expensive | They are less expensive |
| They retain their state indefinitely | They do not retain their state indefinitely |
| They require several transistors | They require less no transistors. |
| Low density | High density |
23. What is Ram Bus technology?
The key feature of Ram bus technology is a fast signaling method used to transfer information between chips. Instead of using signals that have voltage levels of either 0 or V supply to represent the logic values, the signals consist of much smaller voltage swings around a reference voltage, vref. Small voltage swings make it possible to have short transition times, which allows for a high speed of transmission.
24.What are RIMMs?
RDRAM chips can be assembled in to larger modules called RIMMs. It can hold upto 16 RDRAMs.
25. What are RDRAMs?
RDRAMs are Rambus DRAMs. Rambus requires specially designed memory chips. These chips use cell arrays based on the standard DRAM technology. Multiple banks of cell arrays are used to access more than one word at atime. Circuitry needed to interface to the Rambus channel is included on the chip. Such chips are known as RDRAMs.
26.What are the special features of Direct RDRAMs?
- · It is a two channel Rambus..
- · It has 18 data lines intended to transfer two bytes of data at a time.
- · There are no separate address lines.
27. Define ROM?
It is a non-volatile memory. It involves only reading of stored data.
28.What are the features of PROM?
- · They are programmed directly by the user.
- · Faster
- · Less expensive
- · More flexible.
29.Why EPROM chips are mounted in packages that have transparent window?
Since the erasure requires dissipating the charges trapped in the transistors of memory cells. This can be done by exposing the chip to UV light .
30.What are the disadvantages of EPROM?
The chip must be physically removed from the circuit for reprogramming and its entire contents are erased by the ultraviolet light.
31.What are the advantages and disadvantages of using EEPROM?
The advantages are that EEPROMs do not have to be removed for erasure.Also it is possible to erase the cell contents selectively. The only disadvantage is that different voltages are needed for erasing, writing and reading the stored data.
32.What is cache memory?
It is a small, fast memory that is inserted between the larger, slower main memory and the processor. It reduces the memory access time.
33. Differentiate flash devices and EEPROM devices.
| Flash devices | EEPROM devices |
| It is possible to read the contents of a single cell, but it is only possible to write an entire block of cells. | It is possible to read and write the contents of a single cell. |
| Greater density which leads to higher capacity. | Relatively lower density |
| Lower cost per bit. | Relatively more cost. |
| Consumes less power in their operation and makes it more attractive for use in portable equipments that is battery driven. | Consumes more power. |
34.Define flash memory?
It is an approach similar to EEPROM technology. A flash cell is based on a single transistor controlled by trapped charge just like an EEPROM cell.
35. What is locality of reference?
Analysis of programs shows that many instructions in localized areas of the program are executed repeatedly during some time period., and the remainder of the program is accessed relatively infrequently. This is referred to as locality of reference. This property leads to the effectiveness of cache mechanism.
36. What are the two aspects of locality of reference?. Define them.
Two aspects of locality of reference are temporal aspect and spatial aspect. Temporal aspect is that a recently executed instruction is likely to be executed again very
soon. The spatial aspect is that instructions in close proximity to a recently executed instruction are also to be executed soon.
37. Define cache line.
Cache block is used to refer to a set of contiguous address locations of some size. Cache block is also referred to as cache line.
38.What are the two ways in which the system using cache can proceed for a write
operation?
Ø Write through protocol technique.
Ø Write-back or copy back protocol technique.
39. What is write through protocol?
For a write operation using write through protocol during write hit: the cache location and the main memory location are updated simultaneously. For a write miss: For a write miss, the information is written directly to the main memory.
40.When does a readmiss occur?
When the addressed word in a read operation is not in the cache, a read miss
occur.
41. What is write-back or copy back protocol?
For a write operation using this protocol during write hit: the technique is to update only the cache location and to mark it as updated with an associated flag bit, often called the dirty or modified bit. The main memory location of the word is updated later, when the block containing this marked word is to be removed from the cache to make room for a new block. For a write miss: the block containing the addressed word is first brought into the cache, and then the desired word in the cache is overwritten with the new information.
42.What is load-through or early restart?
When a read miss occurs for a system with cache the required word may be sent to the processor as soon as it is read from the main memory instead of loading in to the cache. This approach is called load through or early restart and it reduces the processor’s waiting period.
43.What are the mapping technique?
- Direct mapping
- Associative mapping
- Set Associative mapping
44.What is a hit?
A successful access to data in cache memory is called hit.
45.Define hit rate?
The number of hits stated as a fraction of all attempted access .
46.What are the two ways of constructing a larger module to mount flash chips on a small card?
- Flash cards
- Flash drivers.
47.Describe the memory hierarchy?
48.Define miss rate?
It is the number of misses stated as a fraction of attempted accesses.
49.Define miss penalty?
The extra time needed to bring the desired information into the cache.
50.Define access time for magnetic disks?
The sum of seek time and rotational delay is called as access time for disks. Seek time is the time required to move the read/write head to the proper track. Rotational delay or latency is the amount of time that elapses after the head is positioned over the correct track until the starting position of the addressed sector passes under the read/write head.
51.What is phase encoding or Manchestor encoding?
It is one encoding technique for combining clocking information with data. It is a scheme in which changes in magnetization occur for each data bit. It s disadvantage is poor bit-storage density.
52.What is the formula for calculating the average access time experienced by the processor?
tave=hc +(1-h)M
Where
h =Hit rate
M=miss penalty
C=Time to access information in the cache.
53. What is the formula for calculating the average access time experienced by the processor in a system with two levels of caches?
tave =h1c1(1-h1)h2c2+(1-h1)(1-h2)M
where
h1=hit rate in L1 cache
h2=hit rate in L2 cache
C1=Time to access information in the L1 cache.
C2=Time to access information in the L2 cache.
54.What are prefetch instructions?
Prefetch Instructions are those instructions which can be inserted into a program either by the programmer or by the compiler.
55.Define system space?
Management routines are part of the operating system of the computer.It is convenient to assemble the OS routines into a virtual address space.
56.Define user space?
The system space is separated from virtual address space in which the user application programs reside. The letter space is called user space.
57.What are pages?
All programs and data are composed of fixed length units called pages.each consists of blocks of words that occupies contiguous locations in main memory.
58.What is replacement algorithm?
When the cache is full and a memory word that is not in the cache is referenced, the cache control hardware must decide which block should be removed to create space for the new block that contains the reference word .The collection of rules for making this decision constitutes the replacement algorithm.
59.What is dirty or modified bit?
The cache location is updated with an associated flag bit called dirty bit.
60.What is write miss?
During the write operation if the addressed word is not in cache then said to be write miss.
61.What is associative research?
The cost of an associative cache is higher than the cost of a direct mapped cache because of the need to search all 128 tag patterns to determine whether a given block is in the cache. A search of this kind is called an associative search.
62.What is virtual memory?
Techniques that automatically move program and datablocks into the physical main memory when they are required for execution are called as virtual memory.
63.What is virtual address?
The binary address that the processor used for either instruction or data called as virtual address.
64.What is virtual page number?
Each virtual address generated by the processor whether it is for an instruction fetchis interpreted as a virtual page.
65.What is page frame?
An area in the main memory that can hold one page is called as page frame.
66.What is Winchester technology?
The disk and the read/write heads are placed in a sealed air-filtered enclosure called Winchester technology.
67.What is a disk drive?
The electromechanical mechanism that spins the disk and moves the read/write heads called disk drive.
68.What is disk controller?
The electronic circuitry that controls the operation of the system called as disk controller.
69.What is main memory address?
The address of the first main memory location of the block of words involved in the transfer is called as main memory address.
70.What is word count?
The number of words in the block to be transferred.
71.What is Error checking?
It computes the error correcting code (ECC)value for the data read from a given sector and compares it with the corresponding ECC value read from the disk.
72.What is booting?
When the power is turned on the OS has to be loaded into the main memory which takes place as part of a process called booting.To initiate booting a tiny part of main memory is implemented as a nonvolatile ROM.
73.What are the two states of processor?
- · Supervisor state
- · User state.
74.What is lockup-free?
A cache that can support multiple outstanding misses is called lockup-free.
75.Draw the static RAM cell?
PART-B
1. Write notes on semiconductor RAM memories.
- Internal organization of memory chips
- Static memories
- Asynchronous DRAMs
- Synchronous DRAMs
- Structure Of Larger Memories
- Memory System Considerations
- Rambus Memory
2. Write notes on various types of ROMs.
- ROM
- PROM
- EPROM
- EEPROM
- Flash Memory
3. What are the various types of cache mapping mechanisms? Explain in detail.
- Direct mapping
- Associative mapping
- Set Associative mapping
4. Write notes on secondary storage devices.
- Magnetic hard disks
- Floppy disks
- Optical disks
- DVD
- Magnetic tape systems
- Address Translation
- Diagram
- Explanation
6. What are the various techniques used to improve the performance of cache. Explain it.
- Reducing the miss rate
- Reducing the miss penalty
- Reducing the miss rate or miss penalty using parallelism
- Reducing the time to hit in a cache
7. Explain with neat diagram the internal organization of bit cells in a memory chip.
Hints: Memory cells are usually organized in the form of an array, in which each cell is capable of storing one bit of information. Each row consists a memory word, and all cells of a row are connected to a common line referred to as word line, which is driven by he address decoder on the chip.
8. Discuss the virtual memory management technique in detail
Hints: The data is to be stored in physical memory locations that have addresses different from those specified by the program. The memory control circuitry translates the address specified by the program into an address that can be used to access the physical memory.
9. What is memory interleaving? Explain with neat diagram.
Hints: The main memory of a computer is structure as a collection of physically separate modules each with its own address buffer register and data buffer register, memory access operations may proceed in more than one module at the same time. Thus the aggregate rate of transmission of words to and from the main memory system can be increased.
10.Write brief notes on Optical Disks
- CD Technology
- CD-ROM
- CD-Recordables
- CD-Rewritables
- DVD Technology
- DVD-RAM
11. Explain in detail Magnetic Hard Disks
- Organization And Accessing Of Data On A Disk
- Access Time
- Typical Disks
- Data Buffer/Cache
- Disk Controller
- Software And Operating System Implications
- Floppy Disks
- Raid Disk Arrays
- Commodity Disk Considerations
12. Write notes on Performance Considerations
- Interleaving
- Hit Rate And Miss Penalty
- Caches On Processor Chip
- Other Enhancements
16 Marks
1. Write notes on semiconductor RAM memories.• Internal organization of memory chips
• Static memories
• Asynchronous DRAMs
• Synchronous DRAMs
• Structure Of Larger Memories
• Memory System Considerations
• Rambus Memory
2. Write notes on various types of ROMs.
• ROM
• PROM
• EPROM
• EEPROM
• Flash Memory
3. What are the various types of cache mapping mechanisms? Explain in detail.
• Direct mapping
• Associative mapping
• Set Associative mapping
4. Write notes on secondary storage devices.
• Magnetic hard disks
• Floppy disks
• Optical disks
• DVD
• Magnetic tape systems
5. Write notes on Virtual memories.
• Address Translation
• Diagram
• Explanation
6. What are the various techniques used to improve the performance of cache. Explain it.
• Reducing the miss rate
• Reducing the miss penalty
• Reducing the miss rate or miss penalty using parallelism
• Reducing the time to hit in a cache
7. Explain with neat diagram the internal organization of bit cells in a memory chip.
Hints: Memory cells are usually organized in the form of an array, in which each cell is capable of storing one bit of information. Each row consists a memory word, and all cells of a row are connected to a common line referred to as word line, which is driven by he address decoder on the chip.
8. Discuss the virtual memory management technique in detail
Hints: The data is to be stored in physical memory locations that have addresses different from those specified by the program. The memory control circuitry translates the address specified by the program into an address that can be used to access the physical memory.
9. What is memory interleaving? Explain with neat diagram.
Hints: The main memory of a computer is structure as a collection of physically separate modules each with its own address buffer register and data buffer register, memory access operations may proceed in more than one module at the same time. Thus the aggregate rate of transmission of words to and from the main memory system can be increased.
10.Write brief notes on Optical Disks
• CD Technology
• CD-ROM
• CD-Recordables
• CD-Rewritables
• DVD Technology
• DVD-RAM
11. Explain in detail Magnetic Hard Disks
• Organization And Accessing Of Data On A Disk
• Access Time
• Typical Disks
• Data Buffer/Cache
• Disk Controller
• Software And Operating System Implications
• Floppy Disks
• Raid Disk Arrays
• Commodity Disk Considerations
12. Write notes on Performance Considerations
• Interleaving
• Hit Rate And Miss Penalty
• Caches On Processor Chip
• Other Enhancements
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