DS90UH927Q Datasheet, PDF (27/59 Pages) Texas Instruments – 5MHz - 85MHz 24-bit Color FPD-Link III Serializer with HDCP

DS90UH927Q
FORWARD CHANNEL AND BACK CHANNEL ERROR CHECKING
While in BIST mode, the serializer stops sampling the FPD-Link input pins and switches over to an internal all zeroes pattern. The
internal all-zeroes pattern goes through scrambler, dc-balancing, etc. and is transmitted over the serial link to the deserializer. The
deserializer, on locking to the serial stream, compares the recovered serial stream with all-zeroes and records any errors in status
registers. Errors are also dynamically reported on the PASS pin of the deserializer.
The back-channel data is checked for CRC errors once the serializer locks onto the back-channel serial stream, as indicated by
link detect status (register bit 0x0C[0] - Table 5). CRC errors are recorded in an 8-bit register in the deserializer. The register is
cleared when the serializer enters the BIST mode. As soon as the serializer enters BIST mode, the functional mode CRC register
starts recording any back channel CRC errors. The BIST mode CRC error register is active in BIST mode only and keeps the record
of the last BIST run until cleared or the serializer enters BIST mode again.
FIGURE 22. BIST Waveforms
30193064
INTERNAL PATTERN GENERATION
The DS90UH927Q serializer provides an internal pattern generation feature. It allows basic testing and debugging of an integrated
panel. The test patterns are simple and repetitive and allow for a quick visual verification of panel operation. As long as the device
is not in power down mode, the test pattern will be displayed even if no input is applied. If no clock is received, the test pattern can
be configured to use a programmed oscillator frequency. For detailed information, refer to Application Note AN-2198.
PATTERN OPTIONS
The DS90UH927Q serializer pattern generator is capable of generating 17 default patterns for use in basic testing and debugging
of panels. Each can be inverted using register bits (Table 5), shown below:
1. White/Black (default/inverted)
2. Black/White
3. Red/Cyan
4. Green/Magenta
5. Blue/Yellow
6. Horizontally Scaled Black to White/White to Black
7. Horizontally Scaled Black to Red/Cyan to White
8. Horizontally Scaled Black to Green/Magenta to White
9. Horizontally Scaled Black to Blue/Yellow to White
10. Vertically Scaled Black to White/White to Black
11. Vertically Scaled Black to Red/Cyan to White
12. Vertically Scaled Black to Green/Magenta to White
13. Vertically Scaled Black to Blue/Yellow to White
14. Custom Color (or its inversion) configured in PGRS
Copyright © 1999-2012, Texas Instruments Incorporated
27