# Urgent Help Needed

Joined Jan 15, 2007
1
i am trying to make a 8 by 8 bit multiplier. but the best available IC was of 4 by 4 bit multiplier. The IC# is 74274. so i would like to know that how can i join two 4-bit multipliers IC's to make a circuit of one 8-bit multiplier??
C'mon help me out m really exhausted   #### xelerie

Joined Jan 16, 2007
1
the 8 bit multiplicands A & B could be seperated to pairs of
4 bits (AH,AL) and (BH,BL). The product (16 bits!) could be written as :
P= A x B= (AH,AL) x (BH,BL) = AH x BH +AH x BL + AL x BH+ AL x BL

#### Papabravo

Joined Feb 24, 2006
18,991
the 8 bit multiplicands A & B could be seperated to pairs of
4 bits (AH,AL) and (BH,BL). The product (16 bits!) could be written as :
P= A x B= (AH,AL) x (BH,BL) = AH x BH +AH x BL + AL x BH+ AL x BL
Of course you meant to say that each of the partial products must be shifted appropriately befor the addition takes place. You also forgot to mention that this is an unsigned product of unsigned operands.