Video and television technology has been migrating from analog to digital over the past two decades. The technology used for transmitting data between digital systems has also been migrating from parallel to high-speed serial over the past decade. The SDI video standard is an uncompressed digital video standard that transmits high speed serial video stream through a coaxial cable. Once video is captured by a professional video camera, no matter if it is pre-stored in a media or not, it must go through a few broadcasting systems before reaching consumers. SD-SDI, HD-SDI and 3G-SDI are common video standards used in these professional/broadcasting systems. With SDI, the high resolution video stream can be transmitted through a 75 Ohm coaxial cable for as long as several hundreds meters.
This demo shows the capability of the LatticeECP3™ SERDES with an SD/HD/3G design example. The design is implemented using the LatticeECP3 Video Protocol Board. It includes:
The IP core supports automatic detection between three video standards: 270 Mbps SD-SDI, 1.485 Gbps HD-SDI and 2.97 Gbps 3G-SDI. This design supports two operational modes, Pass-Through mode and Pattern-Generation mode. The mode switching and the controls of these two modes are done by the on-board switch and push-buttons.
When in Pass-Through mode, the serial video stream is received, descrambled and word-aligned by the IP core receiver. Then, the Contrast/Brightness/Hue/Saturation adjustment module can optionally process the received parallel video data. Finally, the parallel video data is sent to the IP core transmitter for data scrambling, line number insertion and CRC insertion before being sent out.
When in Pattern-Generation mode, an internal pattern generator will generate patterns for the IP core transmitter to send out color bars or pathological signals. The receiver can also be enabled in this mode for comparing the received video data with an internal pattern checker. The comparison errors will be sent out through a UART/RS-232 port and captured into a PC text file. A typical application is to generate test patterns and loop them back externally through an SDI cable to the checker. The test patterns can be pathological test patterns for EQU/PLL tests or simply color bar patterns through a very long SDI cable
© Lattice Semiconductor Corporation 2012
