This part of the system is the focus of this application activity, The timing circuits portion of the system provides the 25 s and the 4 s timing outputs as well as a clock output to advance the sequential logic through the four sequential logic produces the sequence of 2-bit Gray codes representing the four states. It also provides trigger outputs to start the long and short timers, The input sequence to this logic represents the four states described by the state dingram. Traffic light and interface unit Traffic al control logic Cetinal logic Red Whicle G G Yellow -Groon Red Sodef Vellow anca Longines Thor Short Completed in Chapter 7 Completed in Chapter 8 Completed in this chapter FIGURE 6-67 Block diagram of the traffic signal control system The combinational logic portion of the system provides outputs to turn the signal lights on and off. While the ones for the condition that keeps the system in the seconda The rate al control system consists of three parts combinational lock Dlaram fog, and magicis, as shown in Figure 6-67. How can the system remain in the fourth state o the second state While there for the condition that produces a transition from the 4. How long can the system remain in the first state 2.
#DIGITAL FUNDAMENTALS 10TH EDITION SYSTEM APPLICATION HINTS CODE#
Thiscono i pressed as T Third State They code is I In this state (St the light is red on the main et and teen on the side street for 25 s when the long timer is on as long as there is a cicleįUNCHO CON LOS eben beter when there is a vehicle on the side rol This contos expressed as the system tramonto For The Gray and in this state the light is red on the and yw the sideset Them remains in this site for swim This conditioned as The Stransitions back to the first die spesso when the settimer pres. The system transition to de ett state when the short time goes.
The wycinam in issue for 43 be the hott timer is on. This con is expressed Second State The Gray bad in this state (S, the light is yellow on the man street and red on the side street. This express + The system transitions to the state weather and there is a vehicle co the side street. In this state (53), the light is goes on the main street and red on the side whether it is oor there is so vehicle de street. Ty The sem vindicates the eppesen San Dichoto Gay come Alone mate, and we The espressores de stam indicate the SD 00 First State The Goods.a more detailed type of diagrams required in which the logie states and the Boolean expressions for the transitions are specified A state diagram graphically shows the sequence of states, the condi tions for each state, and the requirements for transitions from one state to the nexLA though Figure 6-65 is a basic form of state diagram. These requirements withouted in Figure 666 The green light for the main street will stay on for a minimum of 25 songs The preslight for the side street will stay on until there is so vehicle as the et up to a um of 25 The yellow caution light will stay oo for between changes from grees to reda both the main street and the side street Main Main Se M Second Acond Thind 23 second there is no con there is no whicco FIGURE 5-65 Timing requirements for the traffic signals The State Diagram From the timing requirements, a state diagram can be developed to describe the complete system operation. Transcribed image text: TENTH EDITION DIGITAL FUNDAMENTALS FLOYDģ36 FUNCTION OF COMO LOGIC System Application Activity Traffic Signal Control: Part 1 Either to standay used as they te perder bleck dira developed the decran cedidefine dece of pet The combinato Moped in Chand e at the commenced in this activity and the remaining prese Terments The control topics the sequencing of the lights for a finale ing requirements for the system.
0 kommentar(er)
