2 votes 2 votes The circuit shown in figure is using one 4-bit BCD counter and one 4-bit binary counter. The MOD value for the counter is ? Digital Logic gateforum-test-series digital-logic digital-counter + – Parth Shah asked Dec 11, 2018 edited Mar 14, 2019 by ajaysoni1924 Parth Shah 536 views answer comment Share Follow See all 4 Comments See all 4 4 Comments reply parabol commented Dec 11, 2018 reply Follow Share I think the answer is 80. BCD counter counts from 0-9 and starts again (mod 10). Binary counter counts from 0-15 and starts again (mod 16) Lets assume initially Binary counter at value 0000. BCD counter can count on clock pulses, Binary counter increments only when Q3 becomes 1 (ie 8 and 9) See the figure , I am including, we have 8 cycles of 10 different values . Therefore answer is 80. 2 votes 2 votes Parth Shah commented Dec 11, 2018 reply Follow Share Answer given is 160. I also believe that the binary counter will get incremented only when Q3 is 1 i.e. either BCD counter must have 1000 or 1001 value for the working of binary counter. As a result answer should be 80. 0 votes 0 votes parabol commented Dec 11, 2018 reply Follow Share If the binary counter is +ve edge triggered , only 1 value of the binary counter is incremented each cycle (at 8 only).Then we have 16 cycles of 10 different values.Then the answer is 160 1 votes 1 votes Parth Shah commented Dec 11, 2018 reply Follow Share Okay got it. Thanks for clarification. 1 votes 1 votes Please log in or register to add a comment.