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In Carry Propagate Adders, carry propagation is the critical delay. The most efficient scheme is to generate Cout0 (Cin=0) and Cout1(Cin=1) and multiplex the correct output according to Cin. For any radix, the carry output is always 0/1. We present two versions of ternary adders with Cin = (0V, Vdd/2) and Cin = (0V, Vdd) and two versions of quatern...
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... delay must be minimized, either for quaternary FAs or for ternary FAs or for binary FAs. One technique is illustrated in Figure 3: C out = C out0 when C in =0 and C out = C out1 when C in =1. The correct C out is obtained via a multiplexer implemented with transmission gates. ...
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... a log-log scale (except for C L = 0 fF), Fig. 13 presents the input to outputs delays according to C L . Fig. 14 presents C in to C out path is through a multiplexer and an inverter while C in to Sum is just through a multiplexer. The inverter restores the signal and has more driving capability than the multiplexer. It explains why the sum delay is more sensitive to capacitive load. ...
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... The first one is a 14T Full Adder (Fig. 31) • The second one is the typical 28T full adder (Fig.29) • The third one is a MUX-based full adder (Fig. 30) that uses the same circuit style than the ternary and The three binary full adders operate with the same V dd = 0.9V as the quaternary adder. They can also operate with a 0.45V supply, which roughly divide by 4 the dynamic power ...
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... The first one is a 14T Full Adder (Fig. 31) • The second one is the typical 28T full adder (Fig.29) • The third one is a MUX-based full adder (Fig. 30) that uses the same circuit style than the ternary and The three binary full adders operate with the same V dd = 0.9V as the quaternary adder. They can also operate with a 0.45V supply, which roughly divide by 4 the dynamic power dissipation. V dd = 0.45V is a too small power supply value to operate with the three levels of a ternary ...
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... with a 2 fF capacitive load Fig. 32 presents the Input to C out /Sum performance with C L = 2 fF. Fig. 33 presents the C in to C out /Sum performance with the same capacitive load. While the MUX-approach (BFA3) is the best approach for ternary and quaternary adders, it is the worst one for binary adder in terms of delays, power and ΣDi. All powers for 0.45 V dd are roughly 1/4 of the powers of 0.9 V dd versions, leading to PDD slightly ...
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... now present the performance of BFA1 according to capacitive loads and temperature. With a log-log scale, Fig. 34 presents the input to outputs delays according to C L . Fig. 35 presents the same information for C in to outputs delays while Fig. 36 presents the evolution of power according to C L . Fig. 37 presents the ratio delays(C L = 4fF)/delays(0.25fF) when C L is multiplied by 16. It is a figure of the slope of the quasi-linear evolution of ...
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... now present the performance of BFA1 according to capacitive loads and temperature. With a log-log scale, Fig. 34 presents the input to outputs delays according to C L . Fig. 35 presents the same information for C in to outputs delays while Fig. 36 presents the evolution of power according to C L . Fig. 37 presents the ratio delays(C L = 4fF)/delays(0.25fF) when C L is multiplied by 16. It is a figure of the slope of the quasi-linear evolution of delays(C L ). Fig.38 presents the power evolution when C L is ...
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... now present the performance of BFA1 according to capacitive loads and temperature. With a log-log scale, Fig. 34 presents the input to outputs delays according to C L . Fig. 35 presents the same information for C in to outputs delays while Fig. 36 presents the evolution of power according to C L . Fig. 37 presents the ratio delays(C L = 4fF)/delays(0.25fF) when C L is multiplied by 16. It is a figure of the slope of the quasi-linear evolution of delays(C L ). Fig.38 presents the power evolution when C L is multiplied by 16. We still have a quasi linear evolution of delay and ...
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... now present the performance of BFA1 according to capacitive loads and temperature. With a log-log scale, Fig. 34 presents the input to outputs delays according to C L . Fig. 35 presents the same information for C in to outputs delays while Fig. 36 presents the evolution of power according to C L . Fig. 37 presents the ratio delays(C L = 4fF)/delays(0.25fF) when C L is multiplied by 16. It is a figure of the slope of the quasi-linear evolution of delays(C L ). Fig.38 presents the power evolution when C L is multiplied by 16. We still have a quasi linear evolution of delay and power according to C L . However, the binary adder structure ...
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... C L is multiplied by 16. It is a figure of the slope of the quasi-linear evolution of delays(C L ). Fig.38 presents the power evolution when C L is multiplied by 16. ...
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... 4-trit CPAs have been presented in the literature [3], [10], [?] and [17]. Fig. 39 compares the performance of these three CPAs with two variants: the ternary one uses 0-V dd /2 and 0-V dd carry swing, the quaternary one uses 0-V dd /3 and 0-V dd carry swing • While the binary CPA uses more full adders, its estimated chip area is half the chip area of the ternary and quaternary ...
