CY7C9235

The CY7C9235 is a CMOS integrated circuit designed to encode  SMPTE-125M and SMPTE-244M bit-parallel digital characters (or other data formats) using the SMPTE-259M encoding
rules. Following encoding, the characters are output as bit-parallel characters ready for serialization. The encoded outputs of the CY7C9235 are designed to be directly mated to a CY7B9234 HOTLink transmitter, which then converts the bit-parallel characters into a SMPTE-259M compatible high-speed serial data stream.

This device performs both TRS (sync) detection and filtering, data scrambling with the SMPTE-259M X9 + X4 + 1 algorithm, and NRZ-to-NRZI encoding. These functions operate at any character rate from 16- to 40 MHz. For those systems operating with non-SMPTE-259M compliant video streams (or for diagnostic purposes), the scrambler and NRZI encoding functions can be disabled.

DVB-ASI Operation

The CY7C9235 also contains the necessary multiplexers, control inputs, and outputs, to sequence out a DVB-ASI compliant video stream. DVB-ASI operation is enabled through activation of a single input signal. This allows a single serial output port to support both SMPTE and DVB data streams under software or hardware control.

In DVB-ASI mode the CY7C9235 operates with two enable signals (ENA and ENN) to allow data to be presented from either synchronous (clocked) or asynchronous FIFOs. When data is not available, the CY7C9235 ensures that the proper fill character (K28.5) is generated by the attached CY7B9234 serializer.

The CY7C9235 operates from a single +5V or -5V supply. It is available in a 44-pin PLCC space saving package.