数字电路英文版第十一单元课件.ppt

CHAPTER 11 SEQUENTIAL LOGIC APPLICATIONS OF PLDs; §11.1 THE COMPLETE OLMC; In this section, we will discuss the complete OLMC which includes a flip-flop, again using the GAL22V10 and the GAL16V8 as representative PLD devices.;The Output Logic Macrocell (OLMC ) in the GAL22V10;5;1-of-4 multiplexer;6;8;9;10;10;12;13;(a’) The effective logic diagram;15;(b’) The effective logic diagram;17;18;19;20;21;22;Q0 := D0;; §11.3 IMPLEMENTING SHIFT REGISTERS WITH PLDs;25;26;27;Equations;29; [ .c. , 1 , 1 , 1 ] [ 1, 0, 1, 0, 1, 0, 1, 0];;D Q;Solution The ABEL input file is as follows:;Equations;34;35;36; §11.4 IMPLEMENTING COUNTERS WITH PLDs;38;Moore state machine: The output depend only on the internal state and any inputs that are synchronized with the circuit. Counters are examples of the Moore type of state machine.;39;Mealy state machine: The outputs are depend by both the internal state and by inputs that are not synchronized with the circuit. ;40;41;42;43;44;45;46;47;48;49;50;51;52; [ 1 , 0 , 0 , 0 , 1 ] : [ 0, 0, 0 ];;Test_Vectors; [ .c. , 1 , 1 , ] [ 0, 0, 1, ];;Implementing the Counter with an ABEL State Diagram;Defining the States;EXAMPLE 11-5 Develop an ABEL input file using the state diagram format to implement the 3-bit up/down Gray code counter in Figure 11-13. A GAL22V10 is the target device. Solution Notice that we still have the equations defining Clock and Clear.;Module Three_bit_U/D_Gray_code_counter;“State Definitions ;State_diagram QSTATE; §11.5 PLD SYSTEM IMPLEMENTATION;The System; Output;Inputs to the State Control Logic;FLOOR2 : Instruction for the elevator to go to the second floor. (inside the elevator);Outputs from the State Control Logic;DIR : Controls the direction of the movement. DIR = 0, up; DIR = 1, down.;The State Diagram for the Elevator State Control Logi