The simulations to determine the energy dissipation were carried out on the set of 10 random-generated test vectors shown in Table 4.21. In Table 4.22 we report the percentage errors for the energy estimation of the units presented above and the number of transistors for each implementation. The error is computed by expression (4.2) with confidence level of 99%. Table 4.22 also shows that the accuracy of the estimation is independent of the size of the circuit (number of transistors). This confirms the dimension independence property of this approach which is a common feature of the Monte Carlo methods.
n. | vectors | |
1 | x | 10100101111110100101011011000111010010111111010010110 |
d | 10100001100111000110110101001001010000110011100011100 | |
2 | x | 10011001010001101111110010110111001100101000110111111 |
d | 10001010110110011011011011111110000101011011001101110 | |
3 | x | 10111110100010110000101111111101011111010001011000011 |
d | 10011110011101001110011101011011001111001110100111010 | |
4 | x | 11000101100101010100101101000000100010110010101010011 |
d | 11000011101101000011110101110110100001110110100001111 | |
5 | x | 11011001101010000101011001010110101100110101000010110 |
d | 10110001100101111010011101100100011000110010111101010 | |
6 | x | 11110110100110110111010101011001111011010011011011101 |
d | 11000000001110110111011001000100100000000111011011110 | |
7 | x | 11100011111001001000111010100011110001111100100100100 |
d | 11111010101100011011001110011100111101010110001101101 | |
8 | x | 10110111101100001101010101000010011011110110000110110 |
d | 10100110101011000011111000000111010011010101100010000 | |
9 | x | 10000110010001100001001111011101000011001000110000101 |
d | 10001010101011001001001111000010000101010101100100101 | |
10 | x | 10101111010011101111101010110110010111101001110111110 |
d | 10110010100000011000011001000111011001010000001100010 | |
standard | low-power | |||||
unit | Eop [nJ] | e % | FETs | Eop [nJ] | e % | FETs |
radix-4 | 45.5 | 2.1 | 21000 | 26.0 | 1.7 | 16400 |
radix-8 | 47.5 | 4.1 | 31000 | 28.5 | 4.2 | 24900 |
radix-16 | 46.0 | 2.8 | 30400 | 30.0 | 3.3 | 25600 |
radix-512 | 66.5 | 2.1 | 83600 | 55.0 | 2.4 | 68300 |
comb. div/sqrt | 46.0 | 3.6 | 25100 | 29.5 | 2.7 | 23800 |
|