SANDBOX - flipflops

SR (latch): > Q (next) = S + (!R•Q) > S•R = 0 - Output latches to S(1) or R(0) (whichever input was high last) - If both 1, output is usually 1) [ S R | Q (next) ] 0 0 | x 0 1 | 0 1 0 | 1 1 1 | n/a D (latch): > Q (next) = D - Whatever D (input) is, Q (output) will become that when clock rises - Commonly used as a shift register T (toggle): > Q (next) = (T • !Q) + (!T • Q) - Output changes states with each rise in clock. - Only toggles when T is high - Cuts the frequency of clk in half * doesnt seem to be working?* JK (combo of T and SR): > Q (next) = (J • !Q) + (!K • Q) - J is "dominant" over K - If J@K ( J , K are different) then Qnext --> J (like a SR flip flop, but with clock) - If J • K then Q toggles (like T flip flop, but J • K) - If !(J•K) nothing... [ J K | Q (next) ] 0 0 | x 0 1 | j 1 0 | j 1 1 | !Q [ Q Q (next) | J K ] 0 0 | 0 X 0 1 | 1 X 1 0 | X 1 1 1 | X 0

published 9 years ago