AR0331
35
value read at 70
°
C and 55
°
C respectively. Once read, the
slope and y-intercept values can be calculated and used in
Equation 9.
For more information on the temperature sensor registers,
refer to the AR0331 Register Reference.
Embedded Data and Statistics
The AR0331 has the capability to output image data and
statistics embedded within the frame timing. There are two
types of information embedded within the frame readout.
•
Embedded Data:
If enabled, these are displayed on the two rows
immediately before the first active pixel row is
displayed.
•
Embedded Statistics:
If enabled, these are displayed on the two rows
immediately after the last active pixel row is displayed.
Figure 35. Frame Format with Embedded Data Lines Enabled
Image
Register Data
Status & Statistics Data
HBlank
VBlank
Embedded Data
The embedded data contains the configuration of the
image being displayed. This includes all register settings
used to capture the current frame. The registers embedded
in these rows are as follows:
•
Line 1: Registers R0x3000 to R0x312F
•
Line 2: Registers R0x3136 to R0x31BF, R0x31D0 to
R0x31FF
NOTE: All undefined registers will have a value of 0.
The format of the embedded register data transmission is
defined per the embedded data section of the SMIA
Function Specification.
In parallel mode, since the pixel word depth is 12
bits/pixel, the sensor 16-bit register data will be transferred
over 2 pixels where the register data will be broken up into
8 MSB and 8 LSB. The alignment of the 8-bit data will be
on the 8 MSB bits of the 12-bit pixel word. For example, if
a register value of 0x1234 is to be transmitted, it will be
transmitted over two, 12-bit pixels as follows: 0x120,
0x340.
Embedded Statistics
The embedded statistics contain frame identifiers and
histogram information of the image in the frame. This can be
used by downstream auto-exposure algorithm blocks to
make decisions about exposure adjustment.
This histogram is divided into 244 bins with a bin spacing
of 64 evenly spaced bins for digital code values 0 to 2
8
, 120
evenly spaced bins for values 2
8
to 2
12
, 60 evenly spaced
bins for values 2
12
to 2
16
. In HDR with a 16x exposure ratio,
this approximately corresponds to the T1 and T2 exposures
respectively. The statistics found in line 2 are for backwards
compatibility. It is recommended that auto exposure
algorithms be developed using the histogram statistics on
line 1.
The first pixel of each line in the embedded statistics is a
tag value of 0x0B0. This signifies that all subsequent
statistics data is 10 bit data aligned to the MSB of the 12-bit
pixel.
Figure 36 summarizes how the embedded statistics
transmission looks like. It should be noted that data, as
shown in Figure 36, is aligned to the MSB of each word: