ECE221 Laboratory #1 Fall, 1999

Due: Wed.., Nov. 10, 1999; off-campus: ~2 weeks after receipt

The Data Router.

Note: The statement of this assignment in intentionally rather wordy and somewhat verbose. Part of your job is to "translate" this verbal description into a specification and then an implementation of a suitable system.

Beth and Bob want to send 4-bit data "packets" to Ann or Andy, using a common communications link. A MUX is used to select whether Beth or Bob's data is switched into the system, and a DMUX is used to select which of Ann or Andy receives the data. The output of the MUX is connected to source register Regs. Flip flop FFs (the source flip flop) determines whether Beth's or Bob's data is latched into the source register Regs at the next clock pulse, and therefore "sent over the communications link" and latched into Regd, the destination register, at the next clock pulse. Flip flop FFd (the destination flip flop) determines which of Ann or Andy is connected to the data. A momentary closure of the push button PBs "toggles" FFs at the next clock pulse, changing the selection input to the MUX. Similarly, a momentary closure of PBd toggles FFd.

The data to be sent is a 4-bit value, which Beth and Bob enter using a hex keyboard. The data is received by Ann and/or Andy and is viewed in a hex display. The whole system is synchronized with a single clock.

(In the picture below, insert a picture of Regs at the output of the MUX, and change the name Reg to Regd.)


 

Design a system that satisfies the functional requirements of this system. Enter it in Logicworks and test it thoroughly. Print timing wave forms that show the system responding properly to different values input through the hex keyboards and a variety of presses of the two pushbuttons.


Your report must include:

a). A brief description of the design process you used to obtain the circuit. Be sure to point out what steps you took to minimize the amount of hardware required, and the final list of gates used.
b). A printout of the circuit you designed.
c). A printout of simulation wave forms showing that the circuit performs properly under 'all' conditions.
d). A diskette (labelled with your name) that contains the circuit, so we can simulate your system.

Grading Criteria:

*** (85 points) A printout of your circuit along with printouts of simulations demonstrating that the circuit operates properly and satisfies the design requirements.

*** (15 points) Clarity of your explanation, neatness of the report and its overall level of professionalism.

Important note: Always make a copy of your report, in case it gets lost. Bind your reports neatly and professionally -  their appearance DOES matter!