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3 years ago

What are the steps to execute an instruction by cpu?What is the function of DMA controller.

Engineering

1 answer:

JulijaS [17]3 years ago

4 0

Explanation:

1. A sequence of instructions is stored in memory.

2. The memory address wherever the first instruction is found is copied to the instruction pointer.

3. The CPU sends the address within the instruction pointer to memory on the address bus.

4. The CPU sends a “read” signal to the control bus.

5. Memory responds by sending a copy of the state of the bits at that memory location on the

data bus, that the CPU then copies into its instruction register.

6. The instruction pointer is automatically incremented to contain the address of the next

instruction in memory.

7. The CPU executes the instruction within the instruction register.

8. Go to step 3

Steps 3, 4, and 5 are called an instruction fetch. Notice that steps 3 – 8 constitute a cycle, the instruction execution cycle. It is shown graphically below.

A DMA controller can generate memory addresses and initiate memory read or write cycles. It contains several hardware registers that can be written and read by the CPU. These include a memory address register, a byte count register, and one or more control registers.

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25 points!!

adell [148]

Answer 1:

Like most electrical mechanical devices, electric motors have mechanical bearings that eventually wear out.

The graphite brushes and commutator of older DC motors can also wear out over time

Answer2:

Question two is not specific enough!!
Are we talking DC?? Because if so, then yes, nothing will happen. Assuming you are insulted by ground.
Ac is a different story, as the two would light up dangerously and etc.

-your welcome!!

5 0

4 years ago

A rectangular plate casting has dimensions 200mm x 100mm x 20mm. The riser for this sand casting mold is in the shape of a spher

9966 [12]

Answer:

Diameter of riser =6.02 mm

Explanation:

Given that

Dimensions of rectangular plate is 200mm x 100mm x 20mm.

Volume of rectangle V= 200 x 100 x 20 $mm^3$

Surface area of rectangle A

A=2(200 x 100+100 x 20 +20 x 200) $mm^2$

So V/A=7.69

We know that

Solidification times given as

$t=K\left(\dfrac{V}{A}\right)^2$ -----1

Lets take diameter of riser is d

Given that riser is in spherical shape so V/A=d/6

And

Time for solidification of rectangle is 3.5 min then time for solidificartion of riser is 4.2 min.

Lets take $\dfrac{V}{A}=M$

$\dfrac{M_{rac}}{M_{riser}}=\dfrac{7.69}{\dfrac{d}{6}}$

Now from equation 1

$\dfrac{3.5}{4.2}=\left(\dfrac{7.69}{\dfrac{d}{6}}\right)^2$

So by solving this d=6.02 mm

So the diameter of riser is 6.02 mm.

3 0

3 years ago

What will the following segment of code output? score = 95; if (score > 95) cout << "Congratulations!\n"; cout <<

Anarel [89]

Answer:

That's a high score!

This is a test question!

Explanation:

The reason these two lines are printed and not the first one is simple. After the 'IF' condition has been stated, there is no use of parenthesis such as { and } to enclose the next lines. This means that only the first line after the 'IF' condition may be read or skipped depending on whether the condition (score>95) is met. Since the score is not larger than 95, and the 'IF' condition fails, the line 'Congratulations!' is not printed. The next two lines of the code are read as normal because they do not depend on the 'IF' condition.

5 0

3 years ago

The "Crawler" developed to transport the Saturn V launch vehicle from the assembly building to the launch pad is the largest lan

Illusion [34]

Answer:

a) 152000 slugs

b) 2220000 kg or 2220 metric tons

Explanation:

A body with a weight of 4.9*10^6 lbf has a mass of

4.9*10^6 lbm * 1 lbf/lbm = 4.9*10^6 lbm

This mass value can then be converted to other mass values.

1 slug is 32.17 lbm

Therefore:

4.9*10^6 lbm * 1 slug / (32.17 lbm) = 152000 slugs

1 lb is 0.453 kg

Therefore:

4.9*10^6 lbm / (1/0.453) * kg/lbm = 2220000 kg

5 0

4 years ago

A small grinding wheel is attached to the shaft of an electric motor which has a rated speed of 3600 rpm. When the power is turn

Ostrovityanka [42]

Answer: a) 150 rev. b) 2105 rev.

Explanation:

a) Assuming a uniformly accelerated motion, we can use the equivalent kinematic equations, replacing linear variables by angular ones.

In order to get the number of revolutions executed, we can use this:

ωf² - ω₀² = 2 γ Δθ (1)

For the first part, we know that ω₀ = 0 (as it starts from rest).

We can find out the value of angular acceleration γ, just applying the definition of angular acceleration, as the change in angular velocity, regarding time, as follows:

γ = (ωf - ω₀) / Δt (2)

As we would want to use SI units, it is advisable to convert the value of ωf, from rpm to rad/sec.

3600 rev/min . (1min/60 sec) . (2π rad/rev) = 120π rad/sec

Replacing in (2), we get γ:

γ = 120 π / 5 rad/sec² = 24 π rad/sec²

Replacing in (1) and solving for Δθ:

Δθ = 120² π² / 2. 24 π = 300 π rad

As 1 rev = 2π rad, Δθ = 150 rev

b) For the second part, we can use exactly the same equations, taking into account that ω₀ = 120 π rad/sec, and that ωf = 0.

The new value for γ is as follows:

γ = -120π / 70 rad/sec² = -1.71 rad/sec²

Replacing in (1) and solving for Δθ, we get:

Δθ = -120² π² / 2. (-1.71) π = 4210 π rad

As 1 rev = 2π rad, Δθ = 2105 rev

7 0

4 years ago