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WinVCC in Depth
The I2C system test can be run at anytime by clicking Run System I2C Test in the Tools menu.
Figure 11. I2C System Failure
8.4Real-Time Polling
Real-time polling provides polling functions that execute continuously in the background, when enabled via the Real-Time Polling dialog. There are two polling functions. The function that applies to the TVP5154 is
VIDEO-STANDARD AUTO-SWITCH POLLING.
When the TVP5154 detects a change in the input video standard, it automatically switches to operation in the detected standard (which includes all necessary I2C register initialization) for proper decoding of the input video. To enable auto-switch on the TVP5154, the Set Video Standard register must be set to auto-switch mode (Reg 0x28 = 0x00).
If the WinVCC auto-switch polling function is enabled, the detected video standard status from the TVP5154 is polled until a change in the input video standard (or in the TVP5154 sampling mode) is detected. When a change is detected, the video encoder is reprogrammed as needed for the detected standard. Using this feature, the video source can change its video standard and the system displays using the new standard, without user intervention.
When using the TVP5154 EVM with the DM642 and a composite output from the 7311 encoder, it is required to disable auto-switch polling by clicking on the ENABLED button in the Real-Time Polling dialog box as shown in Figure 12.
The real-time polling dialog can also be accessed once WinVCC is up and running by clicking Real-Time Polling in the Tools menu.
SLEU069A –February 2006 –Revised July 2006 | TVP5154EVM User's Guide | 15 |