From: Area/latency optimized early output asynchronous full adders and relative-timed ripple carry adders
Full adder constituting the RCA; RCA type is given alongside | Theoretical cycle time (in ns) for RCAs corresponding to various carry-propagation chain lengths | |||
---|---|---|---|---|
4 Full adders | 8 Full adders | 16 Full adders | 32 Full adders | |
Singh (1981)—strong | 29.22 | 29.22 | 29.22 | 29.22 |
Sparsø and Staunstrup (1993)—strong | 18.52 | 18.52 | 18.52 | 18.52 |
Toms (2006)—strong | 18.08 | 18.08 | 18.08 | 18.08 |
Sparsø and Staunstrup (1993)—weak | 2.06 | 4.12 | 8.24 | 16.48 |
Toms and Edwards (2010)—weak | 2.42 | 4.83 | 9.66 | 19.32 |
Folco et al. (2005)—weak | 1.75 | 3.5 | 7 | 14 |
Balasubramanian and Edwards (2008c)—weak | 0.83 | 1.38 | 2.49 | 4.71 |
Balasubramanian (2015)—weak | 0.62 | 1.04 | 1.87 | 3.53 |
Balasubramanian (2011)—early output | 0.58 | 0.97 | 1.74 | 3.29 |
Seitz (1979) Early output—relative-timed | 0.82 | 1.47 | 2.78 | 5.40 |
AOPT_EO_FA (proposed)—relative-timed | 0.47 | 0.85 | 1.61 | 3.12 |
LOPT_EO_FA (proposed)—relative-timed | 0.45 | 0.82 | 1.55 | 3 |