VL6522

Register description

15/35

5

Register description

5.1

Register interpreter

Register contents represent different data types as described in

Table 4.

Registers not listed in this datasheet should be considered as reserved or read-only and

should not be written to, as this may cause unpredictable results.

The VL6522 registers can be written to using the extension units within the Windows video

class.

All register locations contain an 8-bit byte. However, certain parameters require 16 bits to

represent them and are therefore stored in more than 1 location.

Note:

For all 16 bit parameters, the MSB register must be written before the LSB register.

The data stored in each location can be interpreted in different ways as shown below.

Register contents represent different data types as described in

Table 5.

Float number format

Float 900 is used in ST co-processors to represent floating point numbers in 2 bytes of data.

It conforms to the following structure:

Bit[15] = Sign bit (1 represents negative)

Bit[14:9] = 6 bits of exponent, biased at decimal 31

Bit[8:0] = 9 bits of mantissa

Table 4.

Register naming prefix

Prefix

Description

UIA_BYTE = b

One byte unsigned data

UIA_UINT16 = w

Twobyte data

UIA_UINT16 = uw

Two byte unsigned data

Flag_e(F) = f

One byte data. Only two possible values

UIA_FLOAT = fp

Two byte data. Expect value in Floating Point 16 notation

UIA_INT8 = sb

One byte signed data

Table 5.

Data type

Data type

Description

BYTE

Single field register 8 bit parameter

UINT_16

Multiple field registers - 16 bit parameter

FLAG_e

Bit 0 of register must be set/cleared

CODED

Coded register - function depends on value written

FLOAT

Float Value