Modify the decoding circuit of Figure 12-35 to operate from a 16-line address bus (i.e., add A₁₃, A₁₄, and A₁₅). The four PROMs are to maintain the same hex address ranges.

Figure 12-35

Transcribed Image Text:

A15 A₁4 A13 A12 दददददद..... A11 A10 Control bus E 3-line-to-8-line decoder C B A E3 decoder -OE2 01234567 Decoder selects one PROM chip determined by A₁₁ and A₁ 1b 74ALS138 3 1-of-8 00009999 2 b Ko CS Ao-A10 PROM-0 2K X 8 07-00 [8] T (a) Address bus [16] K1 CS [11] Ao-A₁ PROM-1 2K X 8 07-00 [8] Data bus [8] K2 CS Ao-A10 PROM-2 2K x 8 07-00 [B] K3 Lacs [11] Ao-A10 PROM-3 2K X 8 07-0 [8]