Eccelerators.Video

src/WindowProbe.lvt

namespace Eccelerators.Video

/**
 * Standalone timing/resource probe: 320x240 Gray ramp, two line RAMs and both filters.
 * Not a board design. External controls have no physical pin or I/O timing contract.
 */
@Context(ClockFrequency = 50MHz)
component WindowProbe
{
	// Source and explicit block-RAM neighborhood generator.
	source: PatternSource<320, 240>
	window: Window3x3<320, 240>

	// Borrowed stable source controls and consumer-facing stream outputs.
	enabled: bool
	pattern: int
	public ready: in bool
	public valid: out bool
	public blur: out byte
	public sobel: out byte
	public frameStart: out bool
	public lineEnd: out bool
	public frameEnd: out bool
	public frameId: out uint

	// Owned elastic result register; one common valid for both arithmetic outputs.
	heldValid: bool
	heldBlur: byte
	heldSobel: byte
	heldStart: bool
	heldLineEnd: bool
	heldEnd: bool
	heldId: uint

	/**
	 * Binds enable and pattern; settings must remain stable during a frame.
	 */
	new(enabled: bool, pattern: int)
	{
		this.enabled = enabled
		this.pattern = pattern
		this.source = new PatternSource<320, 240>(enabled, pattern)
		this.window = new Window3x3<320, 240>()
	}

	/**
	 * Connects one clock domain, explicit backpressure and common output metadata.
	 */
	process Wire[]()
	{
		this.source.ready = this.window.upstreamReady
		this.window.inputData = this.source.data as byte
		this.window.inputValid = this.source.valid
		this.window.inputStart = this.source.frameStart
		this.window.inputLineEnd = this.source.lineEnd
		this.window.inputEnd = this.source.frameEnd
		this.window.inputId = this.source.frameId
		this.window.ready = !this.heldValid || this.ready
		this.valid = this.heldValid
		this.blur = this.heldBlur
		this.sobel = this.heldSobel
		this.frameStart = this.heldStart
		this.lineEnd = this.heldLineEnd
		this.frameEnd = this.heldEnd
		this.frameId = this.heldId
	}

	/**
	 * Registers both filters at the same edge; no arithmetic-to-metadata skew.
	 */
	process Filter()
	{
		state Tick {
			if (this.window.ready) {
				this.heldValid = this.window.valid

				if (this.window.valid) {
					this.heldBlur = NeighborhoodMath.Blur(this.window.topLeft, this.window.topCenter,
						this.window.topRight, this.window.middleLeft, this.window.middleCenter,
						this.window.middleRight, this.window.bottomLeft, this.window.bottomCenter,
						this.window.bottomRight)
					this.heldSobel = NeighborhoodMath.Sobel(this.window.topLeft, this.window.topCenter,
						this.window.topRight, this.window.middleLeft, this.window.middleRight,
						this.window.bottomLeft, this.window.bottomCenter, this.window.bottomRight)
					this.heldStart = this.window.frameStart
					this.heldLineEnd = this.window.lineEnd
					this.heldEnd = this.window.frameEnd
					this.heldId = this.window.frameId
				}
			}

			goto Tick
		}
	}
}