6.6 2 Compressor Tree Analysis

3.6. 6:2 COMPRESSOR TREE:- The 6:2 Compressor Tree consists of six inputs I5, I4, I3, I2, I1, I0 and two carry inputs Cin,0, Cin,1.The outputs are Cf, Sf and Cout,0, Cout,1. When the 6:2 compressor trees are cascaded then an extra carry is connected to the second 6:2 compressor tree. The carry outputs of each 6:2 compressor tree connected to the alternative 6:2 compressor trees and so on. The block diagram of 6:2 compressor tree is shown in Fig.3.6 (a). The architecture of 6:2 compressor tree shown in Fig.3.6 (b). The interconnection of 6:2 compressor tree is shown in Fig. 3.6 (c). 6:2 compressor consists of four full adders and one half adder. Here a full adder represents 3:2 counter and half adder represents 2:2 counter. Fig.3.6 (a) Block

When the 7:2 compressor trees are cascaded then an extra carry is connected to the second 7:2 compressor tree. The carry outputs of each 7:2 compressor tree connected to the alternative 7:2 compressor trees and so on. The block diagram of 7:2 compressor tree is shown in Fig.3.7 (a). The architecture of 7:2 compressor tree shown in Fig.3.7 (b). The interconnection of 7:2 compressor tree is shown in Fig. 3.7 (c). 7:2 compressor consists of five full adders. Here a full adder represents 3:2

16:2 Compressor Tree with 4:2 compressors.

3.12. IMPLEMENTATION OF 16i/p, 2o/p by 5:2 COMPRESSOR TREE:-

We are implementing a 16-bit input and two bits as output by using 5:2 compressor tree. Here the inputs ranges from a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8], a[9], a[10], a[11], a[12], a[13], a[14], a[15] and b1(redundant bit). The final outputs are sum, carry. Interconnecting wires are i1, i2, i3, i4, i5, i6, i7. The 16:2 compressor tree designed with 5:2 compressor tree is shown in fig.3.12.The 5:2 compressor trees are denoted with the components are named as u1, u2, u3, u4, u5.the carry from u1 is send to u2, similarly u2 to u3,u3 to u4, u4 to u5.

Fig.3.12. 16:2 Compressor Tree with 5:2