Fast Blanking Operation (pin 16 on SCART)

The fast blanking signal instructs the TV to select either external CVBS information or external RGB information. This is used to impose an on screen display (OSD) presentation (normally RGB) upon a CVBS background. This function is used when using the UHF selector on the RCU.

Fast blanking information has the same nominal phase as the RGB and CVBS signal, and is defined as follows on the SCART connector:

CVBS mode: SCART pin 16 voltage = 0 to 0,4 V (low) RGB mode: SCART pin 16 voltage = 1 to 3 V (high)

Normally the OSD is generated within the MPEG 2 decoder, but the encoder can superimpose OSD (RGB) on top of a CVBS signal emanating from VIN6. The encoder is synchronised to the CVBS signal.

The two fast blanking inputs are associated with the auxiliary RGB/CVBS inputs and the other associated with the Digital Encoder input. These are selected by I²C.

For more information refer to the post SCART Connector Pin Assignments.