FPGA Intellectual Property
PCI Express*, Networking and Connectivity, Memory Interfaces, DSP IP, and Video IP

Video Output Error

Honored Contributor II



I am using two Stratix-III FPGA development boards (from Microtronix) for a HD video system design. One is used to generate HD Video Pattern and transmit it and other one to receive it and display on HD TV.  


For TX FPGA module, I am using video pattern generator (TPG) with image width of 1920x1080, 4:4:4 sampling, 3 parallel planes and controls on separate wires. The output of test pattern generator is connected with CVO (clocked video output) module, which provide data to HDMI TX chip on a daughter board. Since I wanted to generate full HD video pattern at 60 fps, so the clock used by CVO to output data is 148.5 MHz. Inside SOPC, both TPG and CVO use 160 MHz clock to overcome any processing delays. The CVO is configured to output 1080p progressive HD frame with 3 parallel planes, 4:4:4, 24 bit output data, controls on separate wires. 


For RX FPGA module (which is on separate FPGA board), I have designed simple pass through design. Here I am not using any SOPC video processing cores. I just redirect the input video (from HDMI RX chip) to the output port (HDMI TX chip). Here SOPC instantiates only NIOS processor which programs HDMI RX and TX chips using I2C controller. 


I have tested both the FPGA boards individually. That is, when output of TX FPGA board is connected to HD TV, I can see video pattern. Similarly when RX FPGA board is connected to both HD video source (DVD player) and and sink (HD TV), it successfully passes HD video from input to output. 


Problem occurs when I connect output of TX FPGA board to the input of RX FPGA board through HDMI cable. I do not get any output. TV screen shows message "unrecognized video format".  


Can anyone please help me in solving this issue. I do not understand why this is happening and what should I do to fix it. 




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