SDA9410
Preliminary Data Sheet
Input signal processing
Histogram
Line Type Decision
Pixel
Value
Amount of Pixels
> 2*TH_DN_BN
APPLIPM*4
4 * TH_AA
2 *
TH_DN_BN
AA
BC
UNS
. . . . . .
. . .
BC
. . .
4 * TH_LB
line
0
LB
TH_DN_BN (I²C bus parameter)
Figure 21
Histogram and line type decision
Based on the line types the first line of the active area (SLAA, I²C parameter 78h) and
the last line of the active area (ELAA, I²C parameter 79h) is determined. Furthermore the
information about reliability of the SLAA and ELAA value is determined. The reliability
information is readable by I²C Bus of the parameters STATUS_SLAA and
STATUS_ELAA. If STATUS_SLAA/STATUS_ELAA is equal “1” the SLAA/ELAA value
is reliable, otherwise the SLAA/ELAA value is not reliable.
In addition a global reliability signal RELY exists, which is also readable by I²C Bus. The
results of the letter box detection are reliable, if the RELY signal is read as “1”. The
“Reliability evaluation” block determines the RELY signal, which can be influenced by the
I²C Bus parameter TH_MUNSL, TH_AUNS and TH_ALB. The table below explains the
generation of the RELY signal. The thresholds TH_MUNSL, TH_AUNS and TH_ALB are
compared with internal counter values UNSLENGTH, UNSAMOUNT and LBAMOUNT,
respectively. If one of the three conditions is true, the RELY signal is set to not reliable.
UNSLENGTH contains the maximum length of consecutive lines with the line type UNS.
UNSAMOUNT contains the amount of lines with the line type UNS and LBAMOUNT
contains the amount of lines with the line type LB.
RELY
0 (not reliable)
UNSLENGTH > 16 * TH_MUNSL or UNSAMOUNT > 16 * TH_AUNS or
LBAMOUNT > 16 *TH_ALB
1 (reliable)
otherwise
Table 29
Evaluation of the reliability signal RELY
The I²C Bus parameter TH_MA_AA can be used to force the SLAA and ELAA value to
their default values. Therefore the amount of active area line types AA is counted in the
48
Micronas
MICRONAS [ MICRONAS ]
