in CO and Architecture
1,294 views
5 votes
5 votes

A device has been used in DMA. A word of 4 bytes can be transferred when it is available. The memory cycle time is 40 ms and CPU is idle for 10% of its time. What is the data transfer rate of the device for Burst mode and Cycle stealing mode. 

I'm getting

Burst mode - 11.11 B/s 

Cycle stealing - 10 B/s

Is it correct??

in CO and Architecture
1.3k views

4 Comments

@Ashwin Kulkarni In cycle stealing it may be 9.09 it take a time of 11 cycle to transfer 4 byte of data

0
0
How in burst mode it's is 11.11 for 1B
0
0
I AM ALSO GETTING THE SAME
0
0

1 Answer

2 votes
2 votes
Lets's suppose x = data transfer rate and y = memory cycle time

 

% time CPU idle ==  y / ( x + y ) * 100

y / ( x + y ) * 100 = 10 (given)

and y = 40 msec

 

So, 40/40+x * 100 = 10

x = 360 msec

 

So now,

360 msec -------> 4 B

1 msec ----------> 4/360 B

1 sec -------------> 11.11 Byte

Related questions