7

Histogram (CNH) output

Up to 6 KB of histogram data can be read by the host at every frame. Selection of what histogram data is placed

in this 6 KB data area is highly configurable, allowing the amount of the data transferred to be optimized for

different applications. The format of the collected histogram data is called compact normalized histogram (CNH):

•

Compact: Options are available to reduce the amount of data compared to the native “raw” histogram data

•

Normalized: Raw data are adjusted to compensate variations caused by frame-to-frame adjustments

•

Histogram: Primary data is in the form of histograms recording return-signal-strength vs range

Figure 21. Raw histogram (128 bins)

The sensor is highly configurable. The user can program the number of bins, bin width, and also the region-of-

interest. Ambient light level is measured during ranging, and is later removed from the histogram data. A record of

the ambient light level that was removed from each histogram is available in a separate area of the data result

buffer.

Data aggregation options during preprocessing include region-of-interest and subsampling operations both

spatially (zone based), and temporally (on histogram bins).

Table 16. ToF ranging core histogram characteristics

Parameter

Value

Units

Ranging core histogram bin width

250

ps

Ranging core histogram bin equivalent range

37.5

mm

Ranging core number of bins in histogram

128

bins

Table 17. CNH parameters

Setting

Value

Units

CNH buffer maximum size

6160

bytes

Bytes-per-histogram bin

5

bytes

Maximum zones per CNH aggregate

64

zones

Maximum histogram binning factor

8

—

Bytes-per-ambient level

5

bytes

Note:

Details of the CNH configuration options available can be found in the user manual UM3183.

VL53L8CH

Histogram (CNH) output

DS14310 - Rev 3

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