DE0-CV FPGA Board Clock

This repository contains a project where the DE0-CV FPGA board is programmed to function as a digital clock, using 8051 Assembly language. The project demonstrates skills in low-level embedded systems programming, hardware-software interfacing, and real-time control, focusing on the use of 7-segment displays for time and date output.

The code leverages the 8051 microcontroller's architecture to control the DE0-CV board's hardware components, showcasing a hands-on understanding of microcontroller programming and hardware manipulation.

The clock running on the DE0-CV board, displaying the time.

User Guide

Setup

To set the time and date, follow these steps:

1. Enter Set Mode (Time):

   • Flip switch SW0 up to enter set mode for the clock.
   • The current time is entered in 24-hour format. The seconds digit will flash by default.
   • Use push buttons KEY2 to increment and KEY1 to decrement the selected digit.
   • Navigate between digits using KEY3 (left) and KEY0 (right).

2. Enter Set Mode (Date):

   • Flip switch SW1 up to set the date. The year digit is selected by default.
   • Use the same push buttons as above to increment/decrement digits and navigate.
   • Note: If both SW0 and SW1 are up, date setup takes priority.

Validation: The system prevents invalid time and date entries.

Display Modes

By default (i.e. when not in set mode, i.e. when all switches are down), the clock will display the full time hr:min:sec in 24-hour format. All four push buttons can be used to toggle different display modes:

• KEY3 : toggles 12-hour format
• KEY2 : toggles the display of the seconds digit
  • when showing time in 24-hour format, this will blank HEX1 and HEX0
  • when showing time in 12-hour format, this will show either AM or PM depending on the time
• KEY1 : displays the date in MM/DD/YY format for two seconds
• KEY0 : toggles blanking all six hex displays

Tools and Development Environment

• Assembler: The code is compiled using the Keil uVision IDE with its a51 assembler for 8051 microcontrollers.
• Board: The project was tested on the DE0-CV FPGA Board, which interfaces with the 8051 architecture.
• Uploader: A script (b) is provided to upload the compiled .hex file to the FPGA board.

File Details

AssemblyClock
├── MODDE0CV           # Register definitions for the FPGA
├── README.md          # This file
├── clock.asm          # Main assembly code
├── subroutines/       # Assembly subroutines for different functionalities
│   ├── date.asm       # Date handling code
│   ├── display.asm    # 7-segment display logic
│   ├── set_mode.asm   # Clock and date setting modes
│   └── time.asm       # Time handling code
├── gifs/              # GIF demonstrations of clock functionality
│   ├── demo.gif       # Shows clock in action
│   ├── modes.gif      # Shows mode switching
│   └── set.gif        # Shows time setting process
├── a                  # Assembles code into .hex file
├── a51                # Calls assembler for 8051 code
├── b                  # Uploads .hex file to the FPGA
├── backup/            # Backup of assembly code
│   └── clock_backup.asm # Backup of clock.asm
├── clock.hex          # Compiled machine code
├── clock.lst          # Assembler output listing file
└── pdex               # Tool for programming the FPGA