Electronics and Communication Engineering - Microprocessors - Discussion
Discussion Forum : Microprocessors - Section 1 (Q.No. 7)
7.
To multiply a number by 8 in 8085 we have to use
RAL instructionAnswer: Option
Explanation:
When RAL instruction is used once the number is doubled.
Discussion:
20 comments Page 1 of 2.
Priyank said:
8 years ago
How can RAL lead to multiplication as in this instruction the MSB is loaded into carrying flag while moving the whole data to the left by one bit and simultaneously moving the initial carry flag value to the LSB?
Let, Acc-: 01100011b = 99d,
C-: 0
Now, after RAL instruction the value in Acc will be -: 11000110b = 188d not equal to 2 * 99.
So, RAL cannot perform multiplication.
Let, Acc-: 01100011b = 99d,
C-: 0
Now, after RAL instruction the value in Acc will be -: 11000110b = 188d not equal to 2 * 99.
So, RAL cannot perform multiplication.
Meena said:
9 years ago
The answer is simple.
Let's take a value 0100 ---> 4.
1st time: Just apply left shift operation on that value 01000 ---> 8(4 * 2^1).
2nd time: again do the same thing 010000 ---> 16(4 * 2^2).
3rd time: again left shift the value 0100000 ---> 32(4 * 2^3).
So by doing three times left shift we are getting eight times of that value.
So the answer is thrice.
Let's take a value 0100 ---> 4.
1st time: Just apply left shift operation on that value 01000 ---> 8(4 * 2^1).
2nd time: again do the same thing 010000 ---> 16(4 * 2^2).
3rd time: again left shift the value 0100000 ---> 32(4 * 2^3).
So by doing three times left shift we are getting eight times of that value.
So the answer is thrice.
(1)
Chandan jeeva said:
7 years ago
4 is the answer.
00001.
Perform left shift by four times then it will be come 10000=16.
In microprocessor to multiply any number we have to move the data to accumilatorand RAL is used how much time we have to multiply that number account to above calculation.
00001.
Perform left shift by four times then it will be come 10000=16.
In microprocessor to multiply any number we have to move the data to accumilatorand RAL is used how much time we have to multiply that number account to above calculation.
Saurabh said:
1 decade ago
There is no multiplication instruction in the 8085.
These operations are equivalent to multiplying by 2:
1) Shift left by 1 (shifting left by n is multiplying by 2^n).
2) Add the value to itself once.
So 2^3 = 8.
These operations are equivalent to multiplying by 2:
1) Shift left by 1 (shifting left by n is multiplying by 2^n).
2) Add the value to itself once.
So 2^3 = 8.
Afzal said:
9 years ago
@Jaideep,
Last line is simple as that of first two. Initially she takes 4 i.e. 0100 and in the last line we got 32 which is nothing but 8 x 4 = 32. Thats only the answer that we wanted.
Last line is simple as that of first two. Initially she takes 4 i.e. 0100 and in the last line we got 32 which is nothing but 8 x 4 = 32. Thats only the answer that we wanted.
Sagar prajapat said:
9 years ago
Please understand;
1<<1=2 0001<<1= 0010.
1<<2=4 0001<<2= 0100.
1<<3=8 0001<<3= 1000.
1<<1=2 0001<<1= 0010.
1<<2=4 0001<<2= 0100.
1<<3=8 0001<<3= 1000.
(1)
Mansi said:
5 years ago
How can we perform multiplication using RAL if multiplier is odd number i.e,3*5? Please tell me.
Manjunatha said:
8 years ago
@Priyank.
11000110 (B) is = 198 (D), RAL instruction is used as Multiplication.
11000110 (B) is = 198 (D), RAL instruction is used as Multiplication.
Quant said:
9 years ago
Sir I can't understand please can you explain in a simple way.
Khan. said:
9 years ago
Sir, not understand this. Please explain me in detail.
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