VS6724 Datasheet, PDF (51/118 Pages) STMicroelectronics – 2 Megapixel single-chip camera module

VS6724
Programming model and register description
4.2
4.2.1
Note:
Register description
Register interpreter
Register contents represent different data types as described in Register naming prefix.
Table 6. Register naming prefix
Prefix
Description
VP_BYTE = ub
VP_UINT16 = uw
Flag_e(F) = f
Enum = e
VP_FLOAT = fl
VP_INT8 = sb
One Byte unsigned data
Two Byte unsigned data
One byte data. Only two possible values
One Byte data. Specific to module
Two byte data. Expect value in Floating Point 16 notation
One Byte signed data
Registers not listed in this datasheet should be considered as reserved or read-only should
NOT be written to, as this may cause unpredictable results.
The VS6724 I²C write address is 0x20.
All I²C locations contain an 8-bit byte. However, certain parameters require 16 bits to
represent them and are therefore stored in more than 1 location.
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 7.
Table 7. Data type
Data type
Description
BYTE
UINT_16
FLAG_e
CODED
FLOAT
Single field register 8 bit parameter
Multiple field registers - 16 bit parameter
Bit 0 of register must be set/cleared
Coded register - function depends on value written
Float Value
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
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