02-27-2015 04:12 AM
I try to generate a 480i video output with the Xilinx Video Timing Controller.
There seem to be some problems with that core:
1. The signal field_id_out doesn't toggle.
2. The output doesn't seem to be interlaced. Also for the second field HSYNC and VSYNC have a synchronous rising edge and the VBLANK lengths is equal for every field.
Like described in AR#61228 (http://www.xilinx.com/support/answers/61228.html) I added an AXI-Lite interface and set the CONTROL register to enable the generation. But it doesn't help, the field_id_out signal is still LOW the entire time.
Am I missing something? Do I have to set another register via AXI-Lite interface? (I don't need the AXI-Lite interface, for me it would be okay if it would work in constant mode)
Thanks for any help.
02-27-2015 07:35 AM
02-27-2015 07:35 AM
03-02-2015 04:23 AM
setting the Interlaced bit in the generator encoding register indeed works. Now field_id_out signal toggles and AXI-To-VideoOut Core locks. Thank you very much for your help!!
Xilinx should change the description in Table 2-7 of Video Timing Controller User Guide pg016. According to this table default value of register 0x0068 is specified via GUI, which doesn't seem to be correct.
Best regards, Lars
03-02-2015 07:55 PM - edited 03-02-2015 07:56 PM
Oh okay, great! Yeah, we'll be fixing it. Sorry for the inconvenience.
06-30-2016 04:26 AM - edited 06-30-2016 04:27 AM
06-30-2016 10:08 AM
What exactly is unclear still?
From page 38 here:
shows the mapping for the Generator Encoding register (offset 0x68). Bit 6 of that register is the 'Interlaced' bit which defaults to 0. You need to write it to 1, telling the core to generate interlaced content.
07-06-2016 10:43 PM - edited 07-06-2016 10:44 PM
07-13-2016 05:14 AM - edited 07-15-2016 04:34 AM
I am now calling the functions on SDK:
The output on monitor is as shown here.
I noticed that VTC is generating twice the required frequency of sync signals. (HSYNC: 31.25KHz and VSYNC: 100Hz is generated. Ideally, PAL should have HSYNC: 15.625KHz and VSYNC: 50Hz)
What do you suspect is the issue here?
07-13-2016 07:51 PM