The process of _____ determines what volume a system can handle by comparing its performance to standards in the industry.

shusha [124]

Answer:

Direct memory access (DMA) is a process that allows an input/output (I/O) device to send or receive data directly to or from the main memory, bypassing the CPU to speed up memory operations and this process is managed by a chip known as a DMA controller (DMAC).

Explanation:

A defined portion of memory is used to send data directly from a peripheral to the motherboard without involving the microprocessor, so that the process does not interfere with overall computer operation.

In older computers, four DMA channels were numbered 0, 1, 2 and 3. When the 16-bit industry standard architecture (ISA) expansion bus was introduced, channels 5, 6 and 7 were added.

ISA was a computer bus standard for IBM-compatible computers, allowing a device to initiate transactions (bus mastering) at a quicker speed. The ISA DMA controller has 8 DMA channels, each one of which associated with a 16-bit address and count registers.

ISA has since been replaced by accelerated graphics port (AGP) and peripheral component interconnect (PCI) expansion cards, which are much faster. Each DMA transfers approximately 2 MB of data per second.

A computer's system resource tools are used for communication between hardware and software. The four types of system resources are:

I/O addresses
Memory addresses.
Interrupt request numbers (IRQ).
Direct memory access (DMA) channels.

DMA channels are used to communicate data between the peripheral device and the system memory. All four system resources rely on certain lines on a bus. Some lines on the bus are used for IRQs, some for addresses (the I/O addresses and the memory address) and some for DMA channels.

A DMA channel enables a device to transfer data without exposing the CPU to a work overload. Without the DMA channels, the CPU copies every piece of data using a peripheral bus from the I/O device. Using a peripheral bus occupies the CPU during the read/write process and does not allow other work to be performed until the operation is completed.

With DMA, the CPU can process other tasks while data transfer is being performed. The transfer of data is first initiated by the CPU. The data block can be transferred to and from memory by the DMAC in three ways.

In burst mode, the system bus is released only after the data transfer is completed. In cycle stealing mode, during the transfer of data between the DMA channel and I/O device, the system bus is relinquished for a few clock cycles so that the CPU can perform other tasks. When the data transfer is complete, the CPU receives an interrupt request from the DMA controller. In transparent mode, the DMAC can take charge of the system bus only when it is not required by the processor.

However, using a DMA controller might cause cache coherency problems. The data stored in RAM accessed by the DMA controller may not be updated with the correct cache data if the CPU is using external memory.

Solutions include flushing cache lines before starting outgoing DMA transfers, or performing a cache invalidation on incoming DMA transfers when external writes are signaled to the cache controller.

4 0

3 years ago

Read 2 more answers

How are water resources and air adversely affected by environmental degardation?

Nonamiya [84]

Answer:

Environmental degradation is one of the ten threats officially cautioned by the High-level Panel on Threats, Challenges and Change of the United Nations. The United Nations International Strategy for Disaster Reduction defines environmental degradation as "the reduction of the capacity of the environment to meet social and ecological objectives, and needs".[4] Environmental degradation comes in many types. When natural habitats are destroyed or natural resources are depleted, the environment is degraded. Efforts to counteract this problem include environmental protection and environmental resources management.

There are many examples of environmental degradation throughout the world. A recent example is the 2019 Amazon rainforest wildfires. The Amazon makes up 60% of all rainforests. It is the earth's lungs and with it getting destroyed is posing a huge threat to the environment and the whole world. The effects of the deforestation will pose major impacts on the world around us. The constant cutting down of trees is getting rid of our oxygen supply as well as the absorption of co2. With the continuation of deforestation we will have less available oxygen in the world which could have detrimental effects on human health. An alternate issue that results from this is the overconsumption and waste of the paper products that come from those trees. The waste it typically produces does not get recycled, therefore, immense amount of waste is created. An additional harmful result from this is the degradation of the soil. The constant deforestation causes the soil to become less nutrient which will make it harder to be used again.

Explanation:

Environmental degradation is one of the ten threats officially cautioned by the High-level Panel on Threats, Challenges and Change of the United Nations. The United Nations International Strategy for Disaster Reduction defines environmental degradation as "the reduction of the capacity of the environment to meet social and ecological objectives, and needs".[4] Environmental degradation comes in many types. When natural habitats are destroyed or natural resources are depleted, the environment is degraded. Efforts to counteract this problem include environmental protection and environmental resources management.

There are many examples of environmental degradation throughout the world. A recent example is the 2019 Amazon rainforest wildfires. The Amazon makes up 60% of all rainforests. It is the earth's lungs and with it getting destroyed is posing a huge threat to the environment and the whole world. The effects of the deforestation will pose major impacts on the world around us. The constant cutting down of trees is getting rid of our oxygen supply as well as the absorption of co2. With the continuation of deforestation we will have less available oxygen in the world which could have detrimental effects on human health. An alternate issue that results from this is the overconsumption and waste of the paper products that come from those trees. The waste it typically produces does not get recycled, therefore, immense amount of waste is created. An additional harmful result from this is the degradation of the soil. The constant deforestation causes the soil to become less nutrient which will make it harder to be used again.

4 0

3 years ago

What is the lucky 3 digit today

victus00 [196]

That is an interactive question.

4 0

3 years ago

Examine the efficiency the various recovery algorithms used in deadlock handling

sineoko [7]

Solution:

The process of transaction can guarantee the reliability of business applications. Locking resources is widely used in distributed transaction management (e.g; two phase commit, 2PC) to keep the system consistent. The locking mechanism, however, potentially results in various deadlocks. In service oriented architecture, the deadlock problem becomes even worse because multiple transactions try to lock shared resources in the unexpectable way due to the more randomicity of transaction requests, which has not been solved by existing research results. In this paper, we investigate how to prevent local deadlocks, caused by the resource competition among multiple sub-transactions of a gl obal transaction, and global deadlocks from the competition among different global transactions. We propose a replication based approach to avoid the local deadlocks, and a timestamp based approach to significantly mitigate the global deadlocks. A general algorithm is designed for both local and global deadlock prevention. The experimental results demonstrate the effectiveness and efficiency of our deadlock prevention approach. Further, it is also proved that our approach provides higher system performance than traditional resource allocation schemes.

This is the required answer.

4 0

3 years ago

Assume the following variable definition appears in a program:

AnnZ [28]

Answer:

cout << setprecision(2)<< fixed << number;

Explanation:

The above statement returns 12.35 as output

Though, the statement can be split to multiple statements; but the question requires the use of a cout statement.

The statement starts by setting precision to 2 using setprecision(2)

This is immediately followed by the fixed manipulator;

The essence of the fixed manipulator is to ensure that the number returns 2 digits after the decimal point;

Using only setprecision(2) in the cout statement will on return the 2 digits (12) before the decimal point.

The fixed manipulator is then followed by the variable to be printed.

See code snippet below

#include <iostream>

#include <iomanip>

using namespace std;

int main()

{

// Initializing the double value

double number = 12.3456;

//Print result

cout << setprecision(2)<< fixed << number;

return 0;

}

4 0

3 years ago