23-03-2010, 06:43 PM
Plz help n thiz project
thankz
23-03-2010, 06:43 PM
Plz help n thiz project thankz
09-05-2011, 03:07 PM
Hinger.ppt (Size: 137 KB / Downloads: 167) CARRY PROPAGATE ADDER AMIT HINGHER Computational Engineering Basic Principle of a CPA.. Adds two n-bit operands A = (an-1..a0), B=(bn-1..b0) and an optional carry-in cin by performing carry propagation Can be implemented as a combinational circuit using n full adders called the Ripple Carry Adder ARCHITECTURE ARITHMETIC EQUATION 2n cout + S = A + B + cin 2n cout + Σn-1i=0 2i si = Σn-1i=0 2iai+ Σn-1i=0 2ibi + cin = Σn-1i=0 2i (ai + bi) + cin 2ci+1 + si = ai + bi+ ci ; I = 0,1..n-1 where c0 = cin and cout = cn LOGICAL EQUATION gi=ai bi pi=ai bi si=pi ci Ci+1=gi + pi ci ; I = 0,1…n-1 where c0 = cin & cout =cn Complexity Of CPA !!! CPA(Carry propagate Adder) Vs CSA (Carry Save Adder) Comparison (CPA vs CSA) The two resulting adder arrays are similar in hardware requirements, logic structure and critical path lengths Bit arrival time in the CPA is unequal (higher bit arrives later than the lower bits) Comparatively slow Why Carry Propagate Adder ? Performs carry propagation from each bit to higher bit positions Addition results have to be converted to irredundant integer representation Does not occupy a significant area of the chip Less Power Consumption |
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