CY7C9689A

The CY7C9689A HOTLink Transceiver is a point-to-point communications building block allowing the transfer of data
over high-speed serial links (optical fiber, balanced, and unbalanced copper transmission lines) at speeds ranging between 50 and 200 MBaud. The transmit section accepts parallel data of selectable widths and converts it to serial data, while the receiver section accepts serial data and converts it to parallel data of selectable widths. Figure 1 illustrates typical connections between two independent host systems and corresponding CY7C9689A parts. The CY7C9689A provides enhanced technology, increased functionality, a higher level of integration, higher data rates, and lower power dissipation over the AMD AM7968/7969 TAXIchip products.

The transmit section of the CY7C9689A HOTLink can be configured to accept either 8- or 10-bit data characters on each clock cycle, and stores the parallel data into an internal synchronous Transmit FIFO. Data is read from the Transmit FIFO and is encoded using embedded 4B/5B or 5B/6B encoders to improve its serial transmission characteristics. These encoded characters are then serialized, converted to NRZI, and output from two PECL-compatible differential transmission line drivers at a bit-rate of either 10 or 20 times the input reference clock in 8-bit (or 10-bit bypass) mode, or 12 or 24 times the reference clock in 10-bit (or 12-bit bypass) mode.

The receive section of the CY7C9689A HOTLink accepts a serial bit-stream from one of two PECL compatible differential line receivers and, using a completely integrated PLL Clock Synchronizer, recovers the timing information necessary for data reconstruction. The recovered bit stream is converted from NRZI to NRZ, deserialized, framed into characters, 4B/5B or 5B/6B decoded, and checked for transmission errors. The recovered 8- or 10-bit decoded characters are then written to an internal Receive FIFO, and presented to the
destination host system.

The integrated 4B/5B and 5B/6B encoder/decoder may be bypassed (disabled) for systems that present externally
encoded or scrambled data at the parallel interface. With the encoder bypassed, the pre-encoded parallel data stream is converted to and from a serial NRZI stream. The embedded FIFOs may also be bypassed (disabled) to create a reference-locked serial transmission link. For those systems requiring even greater FIFO storage capability, external FIFOs may be directly coupled to the CY7C9689A through the parallel interface without the need for additional glue-logic.

The TTL parallel I/O interface may be configured as either a FIFO (configurable for depth expansion through external FIFOs) or as a pipeline register extender. The FIFO configurations are optimized for transport of time-independent (asynchronous) 8- or 10-bit character-oriented data across a link. A Built-In Self-Test (BIST) pattern generator and checker allows for testing of the high-speed serial data paths in both the transmit and receive sections, and across the interconnecting links.

HOTLink devices are ideal for a variety of applications where parallel interfaces can be replaced with high-speed,
point-to-point serial links. Some applications include interconnecting workstations, backplanes, servers, mass storage, and video transmission equipment.