vlfd-rs

vlfd-rs is a Rust driver for a VeriComm-compatible USB interface board. The 4.x API models board access through explicit sessions:

• Board: owns the USB connection and cached device state
• IoSession: handles VeriComm FIFO transfers
• ProgramSession: handles FPGA programming transfers
• Programmer: convenience wrapper for bitstream upload flows
• VeriCommFrame: names the fixture's four-word, 64-lane sample boundary
• Licence: derives a board-specific activation key from caller-owned credentials

Features

• Pure-Rust USB transport powered by nusb
• Explicit board / I/O / programming session boundaries
• Fixed-size rolling transfer windows for sustained VeriComm streaming
• Reusable-buffer output APIs for lower-allocation I/O paths
• High-level configuration refresh and write helpers
• Bitstream upload support for the integrated FPGA programmer
• Hotplug callbacks powered by a nusb-based polling watcher
• Deterministic board enumeration and selection by USB location or serial number

Quick Start

use vlfd_rs::{Board, IoConfig, Licence, Result};

fn main() -> Result<()> {
    let mut board = Board::open()?;
    let customer_id = 0x1234; // Replace with your issued customer identifier.
    let mut io = board.configure_io(&IoConfig::new(Licence::CustomerId(customer_id)))?;

    let tx = vlfd_rs::VeriCommFrame::from_bits(0x1234);
    let rx = io.transfer_frame(tx)?;
    println!("rx={:#018x}", rx.bits());

    io.finish()?;
    Ok(())
}

Programming Example

use std::path::Path;
use vlfd_rs::{Programmer, Result};

fn main() -> Result<()> {
    let mut programmer = Programmer::open()?;
    programmer.program(Path::new("path/to/bitstream.txt"))?;
    programmer.close()?;
    Ok(())
}

Installation

Add the crate to your Cargo.toml:

[dependencies]
vlfd-rs = "4"

API Notes

• The old monolithic Device API was removed in 3.0
• 4.0 removes embedded credentials; callers must provide a customer ID or key
• Board::open() requires exactly one connected board; use Board::enumerate() and Board::open_selected() when multiple boards are present
• Rolling windows are fixed-size: use io.transfer_window(words, capacity)?
• The old batch transfer helpers are removed in favor of the rolling window API
• Transport remains blocking from the public API perspective
• Internally the USB layer uses nusb and MaybeFuture::wait()

Benchmarking

cargo run --example bench_transfer -- cpu --words 1024 --iterations 200000
cargo run --example bench_transfer -- device --words 512 --iterations 1000

License

Apache-2.0