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Unformatted text preview: nting J-K FF with a D FF: 1) K-Map of Q+ = F(J, K, Q) 2,3) Revised K-map using D's excitation table its the same! that is why design procedure with D FF is simple! JK Q 0 1 00 0 1 01 0 0 11 1 0 J 10 1 1 K Q+ = D = JQ + KQ
Resulting equation is the combinational logic input to D to cause same behavior as J-K FF. Of course it is identical to the characteristic equation for a J-K FF. L4: 6.111 Spring 2004 Introductory Digital Systems Laboratory 20 System Timing Parameters Parameters In D Q Combinational Logic D Q Clk Clk Register Timing Parameters Tcq : worst case rising edge clock to q delay Tcq, cd: contamination or minimum delay from clock to q Tsu: setup time Th: hold time
L4: 6.111 Spring 2004 Logic Timing Parameters Tlogic : worst case delay through the combinational logic network Tlogic,cd: contamination or minimum delay through logic network Introductory Digital Systems Laboratory 21 Delay in Digital Circuits Circuits VDD Ron Vout CL Ron Vout CL VDD (a) Low-to-high
R (b) High-to-low vout C review vin tp = ln (2) W = 0.69 RC
22 L4: 6.111 Spring 2004 Introductory Digital Systems Laboratory System Timing (I): Minimum Period Period CLout In D Q Combinational Logic D Q Clk CLK
Th Th Tsu Clk IN
Tsu Tcq Tcq,cd Tlogic Tcq Tcq,cd Tsu2 FF...
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This note was uploaded on 07/21/2009 for the course EECS 6.111 taught by Professor Prof.ananthachandrakasan during the Spring '04 term at MIT.
- Spring '04