GS9060 datasheet(44/61 Pages) GENNUM

44 / 61 page

GS9060 Data Sheet

22208 - 8

January 2007

44 of 61

3.10.5.1 Video Standard Error Detection

If a mismatch between the received SMPTE 352M packets and the calculated

video standard occurs, the GS9060 will indicate a video standard error by setting

the VD_STD_ERR bit of the ERROR_STATUS register HIGH.

3.10.5.2 EDH CRC Error Detection

The GS9060 calculates Full Field (FF) and Active Picture (AP) CRC words

according to SMPTE RP165 in support of Error Detection and Handling packets in

SD signals.

These calculated CRC values are compared with the received CRC values. If a

mismatch is detected, the error is flagged in the AP_CRC_ERR and/or

FF_CRC_ERR bits of the ERROR_STATUS register. These two flags are shared

between fields 1 and 2.

The AP_CRC_ERR bit will be set HIGH when an active picture CRC mismatch has

been detected in field 1 or 2. The FF_CRC_ERR bit will be set HIGH when a full

field CRC mismatch has been detected in field 1 or 2.

EDH CRC errors will only be indicated when the device is operating in SMPTE

mode, and when the device has correctly received EDH packets.

SMPTE RP165 specifies the calculation ranges and scope of EDH data for

standard 525 and 625 component digital interfaces. The GS9060 will utilize these

standard ranges by default.

If the received video format does not correspond to 525 or 625 digital component

video standards as determined by the flywheel pixel and line counters, then one of

two schemes for determining the EDH calculation ranges will be employed:

1. Ranges will be based on the line and pixel ranges programmed by the host

interface; or

2. In the absence of user-programmed calculation ranges, ranges will be

determined from the received TRS timing information.

The registers available to the host interface for programming EDH calculation

ranges include active picture and full field line start and end positions for both

fields. Table 3-12 shows the relevant registers, which default to '0' after device

reset.

If any or all of these register values are zero, then the EDH CRC calculation ranges

will be determined from the flywheel generated H signal. The first active and full

field pixel will always be the first pixel after the SAV TRS code word. The last active

and full field pixel will always be the last pixel before the start of the EAV TRS code

words.

GS9060 Datasheet(PDF) 44 Page - Gennum Corporation