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Data Measurement (DMEAS)

ADE3700

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2.9

Data Measurement (DMEAS)

The Data Measurement (DMEAS) module measures several characteristics of the data and sync

signals. Data measurements are taken over a programmable window as defined by an upper left

(mix_x, min_y) and a lower right (max_x, max_y), which may be the whole frame. Measurements

are programmable either per color channel or over all color channels.

This module computes all measurements of sync and data format that are done in the INCLK

domain. The Sync Measurement module does measurements in the XCLK domain. The INCLKS

per DE measurement does not use the window feature. It measures the number of INCLK per DE

and returns the result for every line.

All unused or reserved bits will return as zero.

Windows are relative to Sync pulses. A window defined from (0,0) - (0xFFF, 0xFFF) would go from

sync to sync. The reference edge to use, rising or falling, is also programmable per X and Y

coordinates. SMUX should be configured to provide a positive polarity sync to the DMEAS block. All

window enables are reset to 0 and will always be reset on the rising or falling edge of the sync

pulse.

Most algorithms can be run over separate or all color channels. Most algorithms also contain a

threshold value to zero out noise and/or amplify edges. Algorithm, Color, Threshold, or Window

Control changes are accepted at the end of a valid measurement so that they do not affect the

current measurement in progress.

Software can request measurements in one of two ways:

1. All measurements, except DE_Size, are performed in One-shot mode, which is synchronous in

respect the microcontroller.

2. The DE_Size measurement can be set either to One-shot or Free-running modes. Free-

running mode is asynchronous in respect to the microcontroller.

In One-shot mode, the block should indicate that the measurement is valid through an auto clear of

the start condition.

In Free-running mode, the block should indicate that the measurement is valid through a polling

bit. In Free-running mode, a Freeze bit is provided to freeze the results. Measurements still continue

with the polling bit active, however, they are not updated if the Freeze bit is set.

2.9.1

Edge Intensity

The Edge Intensity measurement is the sum of the absolute value of the delta between adjacent

pixels. A programmable threshold is applied to zero out noise and amplify edges. Equation:

Delta_val = abs(pixelA - pixelB) - threshold;

Delta_val = Delta_val < 0? 0: Delta_val;

Sum += Delta_val;

For all 3 color channels: Sum += Delta_val on Red channel + Delta_val on Green channel +

Delta_val on Blue channel

2.9.2

Pixel Sum

The Pixel Sum is the sum of all selected pixels for either a specific color channel or all color

channels within the window specified.

2.9.3

Minimum/Maximum Pixel

This function reports the minimum and maximum pixel found within the specified window.

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