基于DE1 Altera板卡的IC测试仪：能否实现PC界面向VHDL输入变量？

Absolutely, your proposed workflow is totally feasible—this is a standard pattern for FPGA-driven test systems, and the DE1 Altera board has all the hardware you need to make this happen. Let’s walk through each step of your plan, along with practical implementation details:

Breakdown of Your Workflow #

1. Program the FPGA and Boot the Device #

This is straightforward with the DE1 board. After synthesizing your VHDL design in Quartus, you can program the FPGA via JTAG (using the USB-Blaster cable included with the DE1) or store the configuration in the on-board EPC configuration chip for automatic boot on power-up. Once programmed, the FPGA will initialize its internal logic and wait for communication with your PC.

2. FPGA Triggers a PC UI Popup #

To make this work, you’ll need a communication link between the FPGA and PC. The simplest and most reliable option here is UART (serial communication):

• The DE1 board has an RS-232 port that can be connected to your PC via a USB-to-serial adapter (some variants even have a built-in USB-UART bridge).
• In your VHDL code, implement a basic UART transmitter module. When the FPGA finishes booting, send a predefined trigger signal (like the string "READY_FOR_INPUT" ) over the serial port.
• Your C++ UI program will run in the background (or start automatically on PC boot) and continuously listen to the serial port. When it detects the trigger signal, it pops up your input dialog.

Alternatively, you could reverse the flow: start the C++ program first, have it send a "CHECK_FPGA" signal, and wait for the FPGA’s response to trigger the UI. Either way works—serial communication is trivial to implement on both ends.

3. Pass User Input to the VHDL Program #

Once the user enters their parameters (e.g., test voltage levels, test cycle counts, pin configurations), your C++ UI will format the data and send it over the same serial link to the FPGA:

• On the C++ side, use a serial library (like QSerialPort if you’re using Qt for the UI, or Windows’ native Win32 serial API) to send the data. You can use ASCII text (easy to debug) or binary data (more efficient for numeric values).
• In VHDL, add a UART receiver module that converts the incoming serial data into parallel values stored in internal registers. Add a simple handshake mechanism: after the FPGA receives all parameters, send an "ACK" signal back to the PC to confirm successful reception.
• Lock the received parameters into dedicated test control registers (use a synchronous load signal to avoid mid-test parameter changes) so your VHDL test logic can access them reliably.

4. Initiate IC Testing #

Once the parameters are loaded, your VHDL test logic can kick off the test sequence via a state machine:

• Design a state machine that transitions from an IDLE state to a TESTING state when it detects the parameters are loaded (e.g., via a PARAMS_LOADED flag from the UART receiver).
• The test logic can then execute your desired IC tests: apply power to the DUT, send test vectors, read output signals, compare against expected values, and log results. You can even extend the workflow to send test results back to the C++ UI for display.

Key Considerations for Success #

• Communication Reliability: Add parity checks or simple checksums to your serial data to catch transmission errors—critical for ensuring test parameters are correct.
• UI Simplicity: For a basic tester, a C++ UI with a few input fields (numeric boxes, dropdowns for test modes) and a "Start Test" button is all you need. Qt is a great choice here because it’s cross-platform and has excellent serial support out of the box.
• VHDL Module Reusability: Use modular VHDL code—separate the UART communication, parameter registers, and test logic into distinct modules. This makes debugging and future modifications much easier.
• Debugging: Test the serial communication first (send/receive dummy data between PC and FPGA) before integrating the test logic. Use Quartus’ SignalTap II tool to monitor internal FPGA signals and verify parameters are loaded correctly.

Your plan is solid—this is exactly how many small-scale FPGA test systems are built. With a bit of work on the serial communication and UI integration, you’ll have a functional IC tester up and running in no time.

内容的提问来源于stack exchange，提问作者D.P