Purplebox Simulator

This project would define a hardware abstraction of the purplebox, and using that abstraction create a simulation of the purplebox at the level of the hardware abstraction. This would allow students to debug purplebox programs without needing to be physically next to a device. There is a real need for simulation of hardware at the functional level of the software API anytime that you are developing software to run on hardware being developed concurrently. You can not wait until the hardware is fully functional to start software development. The initial stages of software development and testing will have to be done against a hardware simulation implemented in software entirely, simplified hardware, or a mixture of both. The creation of this simulation is often a small, or significant, development project in itself.

Application developers would code to a hardware abstraction layer (HAL) API. There will be two versions of the software: real and simulated purplebox. An application should be able to select its environment (real or simulated purplebox) during startup. Any calls to the simulated purplebox would be handled entirely in software. The project would simulate as many aspects of the purplebox hardware as possible. The real purplebox version would be functions working directly with the hardware. The HAL API that you design should simplify aspects of purplebox usage, such as, working with the D/As and A/Ds. This would make it easier to build purplebox applications.

For the simulated purplebox, there will be a simulation side (SIM) API that allows the developer to programmatically get access to the values output by the hardware, and set the values that the hardware would read in. This would be the same interface that the simulated purplebox user interface would use to display the state of the simulation and allow the user to provide simulated input.

Some features that could be considered for the purplebox simulator are listed below. The exact set of features will be decided through discussion with the instructor.

Features

• D/A and A/D support
  • HAL API
    • Initialization and seutp of channels
    • Input and output as raw binary values, signed and unsigned integers, fixed point values and floating point values
    • Output bounds checking with option to clip, ignore request, or throw an exception on error
    • Support for periodic input and output of values with variable buffer size, options for handling overrun and underrun of buffers such as input overwrite or repeated output, or calling registered callback functions on error
  • SIM API
    • Set analog voltages on A/D inputs
    • Read analog voltages on D/A outputs
  • Display of analog input and output values as signed and unsigned integers, and floating point values, timed traces of these values
• DIO support
  • HAL API
    • Initialization and seutp of channels
    • Input and output in variable bit widths from single bit to full width of channel
    • Output bounds checking with option to ignore out of range bits, ignore request, or throw an exception on error
    • Support for periodic input and output of values with variable buffer size, options for handling overrun and underrun of buffers such as input overwrite or repeated output, or calling registered callback functions on error
  • SIM API
    • Set digital input bits in variable bit widths from single bit to full width of channel
    • Read digital output bits in variable bit widths from single bit to full width of channel
  • Display of digital input and output values in binary, hex, integer, timing diagram traces of bits
• Simulated interrupt generation

Deliverables

A zipfile containing the following:

• Word file containing
  • Documentation for the purplebox hardware abstraction layer API
  • Documentation for the purplebox simulation API
  • User information for how to use the API in both simulation and with a real purplebox
  • Design documentation for the simulator
  • Instructions for rebuilding the API code for both the HAL and SIM APIs
• Fully documented source code for the purplebox simulation
• Momentics project for rebuilding the APIs
• Example programs using the new APIs