TLC34075-135FN Datasheet, PDF (32/52 Pages) Texas Instruments – Video Interface Palette Data Manual

Table 10. Test Register Bit Definitions for Analog Test
BIT DEFINITION
D7: Red select
D6: Green select
D5: Blue select
D4: 145-mV reference select
D3: Result
READ/WRITE
R/W
R/W
R/W
R/W
R
Table 11. D<7:4> Bit Coding for Analog Comparisons
D<7:4>
OPERATION
IF D3 = 1
0000 Normal operation
Don’t care
1010 Red DAC compared to blue DAC
Red > blue
1001 Red DAC compared to 145-mV reference
Red > 145 mV
0110 Green DAC compared to blue DAC
Green > blue
0101 Green DAC compared to 145-mV reference Green > 145 mV
NOTE: All the outputs have to be terminated to compare the voltage.
IF D3 = 0
Don’t care
Red < blue
Red < 145 mV
Green < blue
Green < 145 mV
IOR or IOG
+
IOB or 145 mV
–
BLANK
(Internal Signal)
DQ
D3
C
Figure 14. Internal Comparator Circuitry for Analog Test
The result of the analog comparison is strobed into D3 at the falling edge of an internal signal derived from
the input BLANK signal. In order to have stable inputs to the comparator, the DAC should be set to a constant
level between syncs. For normal operation, data flow check, and screen integrity test, D<7:4> must be set
to zero.
2–20