I. Introduction

The purpose of this lab is to implement a soda machine. The cost of the soda is 75 cents. Your machine will accept quarters, dimes, and nickels. As the user feeds coins into the machine you will need to keep tract of how much was inserted. Once you have collected at least 75 cents, you will release a soda. To simplify this lab you will not be required to give out change. There are five inputs to the system and one output. They are as follows:

• Enable: basically acts as a on/off switch. When signal is low the circuit is "off"
• RST: it will clear the accumulator and reset release to 0.
• Quarter: indicates the user has inserted 25 cents into the machine and will increase the accumulator accordingly.
• Dime: indicates the user has inserted 10 cents into the machine and will increase the accumulator accordingly.
• Nickle: indicates the user has inserted 5 cents into the machine and will increase the accumulator accordingly.
• Release: when this signals is equal to 1 a soda will be release.

II. Implementation

You will start with an FSMD then split it into a controller and datapath (FSM +D). The controller is an FSM which issues commands to the datapath based on the current state and the external inputs. This can be a behavioral description. The datapath contains a netlist of functional units like multiplexors, registers, adders and a comparator, and hence this design is structural.

III. Downloading

Once you have verified your results using Aldec HDL, check out an XS40 board from the T.A. Download your code and verify your results.