Building a DIY Digital Clock with the EPM7160SLC84-10N FPGA
In the world of digital electronics, FPGAs (Field-Programmable Gate Arrays) offer immense flexibility and power. One such versatile FPGA is the EPM7160SLC84-10N, which can be used for a range of applications, including creating custom digital circuits. In this article, we’ll explore how to use the EPM7160SLC84-10N to build a simple digital clock. This project will provide hands-on experience with FPGA programming and digital design, ideal for enthusiasts looking to delve deeper into digital electronics.

Understanding the EPM7160SLC84-10N FPGA
The EPM7160SLC84-10N is a member of the MAX 7000 series from Altera (now part of Intel). It features 160 macrocells, a maximum clock frequency of 100 MHz, and a wide range of I/O options. Its programmable nature allows you to implement complex digital logic circuits and custom functionalities. This FPGA is ideal for learning about digital design and implementing custom digital systems like our digital clock project.

Materials Needed
EPM7160SLC84-10N FPGA
7-segment displays (4 pieces)
74HC595 shift registers (2 pieces)
Push-button switches (for setting time)
16 MHz crystal oscillator
Resistors (220Ω, 1kΩ)
Capacitors (10µF, 100nF)
Breadboard and jumper wires
Power supply (5V DC)
FPGA development board (if available)
JTAG programmer
Circuit Design and Assembly
Design the Digital Clock Circuit: The goal is to create a digital clock that displays hours and minutes on four 7-segment displays. The EPM7160SLC84-10N FPGA will handle the timing and display control, while the 74HC595 shift registers will drive the 7-segment displays.

Clock Signal Generation: Use a 16 MHz crystal oscillator to provide the clock signal to the FPGA. This clock frequency will be divided down within the FPGA to create a 1 Hz signal used for updating the seconds.

7-Segment Display Control: The FPGA will control the 7-segment displays via the 74HC595 shift registers. Connect the serial data output of one shift register to the serial data input of the next. This serial connection will allow the FPGA to control all four displays using just three I/O pins (data, clock, and latch).

Push-Button Switches: Integrate push-button switches for setting the time. These switches will be connected to the FPGA's input pins, and the FPGA will handle the logic to increment and set hours and minutes.

Assemble the Circuit: Place the components on a breadboard. Connect the 16 MHz crystal oscillator to the FPGA's clock input. Wire the 74HC595 shift registers to the FPGA, ensuring proper connections for data, clock, and latch signals. Connect the 7-segment displays to the outputs of the shift registers. Set up the push-button switches and connect them to designated FPGA input pins.

Programming the FPGA: Using FPGA design software (e.g., Quartus II), create a design that includes:

A clock divider to generate a 1 Hz signal from the 16 MHz clock.
Counters to keep track of hours and minutes.
Logic to control the 74HC595 shift registers and drive the 7-segment displays.
Debouncing logic for the push-button switches.
Compile the design and upload it to the FPGA using a JTAG programmer.

Testing the Clock: Power the circuit and observe the 7-segment displays. The digital clock should display the current time and update every second. Use the push-button switches to set the time. Ensure that the FPGA correctly increments and displays hours and minutes.

Fine-Tuning: Adjust the FPGA design as needed to improve the clock's accuracy or add features like an alarm function. You can also experiment with different display multiplexing techniques to optimize performance.

Conclusion
Using the EPM7160SLC84-10N FPGA to build a digital clock provides an excellent introduction to FPGA programming and digital circuit design. By interfacing with 7-segment displays and shift registers, you gain hands-on experience with key digital design concepts and FPGA capabilities. This project not only enhances your understanding of digital electronics but also demonstrates the flexibility and power of FPGAs in creating custom digital systems. Whether you're a beginner or an advanced hobbyist, building a digital clock with the EPM7160SLC84-10N is a rewarding way to explore the world of programmable logic.
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