HDMP-1646

The HDMP-1636/46 transceiver is a single silicon bipolar integrated circuit packaged in a plastic QFP package. It provides a low-cost, low-power physical layer solution for 1250 MBd Gigabit Ethernet or proprietary link interfaces. It provides complete Serialize/ Deserialize for copper transmission, incorporating both the Gigabit Ethernet transmit and receive functions into a single device. This chip is used to build a high speed interface (as shown in Figure 1) while minimizing board space, power and cost. It is compatible with the IEEE 802.3z specification. The transmitter section accepts 10-bit wide parallel TTL data and multiplexes this data into a high speed serial data stream. The parallel data is expected to be 8B/10B encoded data, or equivalent.

This parallel data is latched into the input register of the transmitter section on the rising edge of the 125 MHz reference clock (used as the transmit byte clock). The transmitter section's PLL locks to this user supplied 125 MHz byte clock.

This clock is then multiplied by 10, to generate the 1250 MHz serial signal clock used to generate the high speed output. The high speed outputs are capable of interfacing directly to copper cables for electrical transmission or to a separate fiber optic module for optical transmission.

The receiver section accepts a serial electrical data stream at 1250 MBd and recovers the original 10-bit wide parallel data. The receiver PLL locks onto the incoming serial signal and recovers the high speed serial clock and data.

The serial data is converted back into 10-bit parallel data, recognizing the 8B/10B comma character to establish byte alignment. The recovered parallel data is presented to the user at TTL compatible outputs. The receiver section also recovers two 62.5 MHz receiver byte clocks which are 180 degrees out of pha