pi90sd1636 Pericom Semiconductor Corporation, pi90sd1636 Datasheet - Page 6

• Manufacturer Part Number: pi90sd1636
• Description: Ic Serdes Gig Eth Txrx 64-lqfp
• Manufacturer: Pericom Semiconductor Corporation

PI90SD1636A
SERDES Gigabit Ethernet Transceiver
Functional Block Description
Input Data Latch
The input data latch block latches the 10-bit TTL input parallel byte, TX<9:0>, on the rising edge of the 125 MHz user-provided
TX_CLK into the holding registers.
Parallel-to-Serial Converter
The received 10-bit TTL parallel input byte is converted to serial PECL level data stream by the parallel-to-serial block, and is trans-
mitted differentially to the line driver block at 1.25 Gbps. The 8b/10b encoded data is transmitted sequentially with bit 0 being sent
first.
Clock Generator
The 125 MHz signal used for clocking the serial outputs is generated by the TX PLL block based on the user-provided TX_CLK.
This clock should have a ±100 ppm tolerance.
Internal Loopback
When EWRAP is set to a logic HIGH, the serial data stream generated by the transmitter is looped back to the receiver path, instead
of going out to the DOUT± pins. When in loopback mode, a static logic 1 is transmitted at the line driver (DOUT+ is HIGH and
DOUT- is LOW).
Signal Detect
Signal detect block is used to sense the serial input data stream at pins DIN±. If the serial input is lower than 50mV differentially, this
block deasserts SIG_DET and sets the output, RX<9:0>, to all logic ones. When the serial input at pins DIN± is greater than 50mV,
the signal is directed to the receive path.
Equalizer and Slicer
The signal received from the line (DIN± pins) is distorted by the cable bandwidth. In order to maintain a low bit-error rate, an equalizer
is used to compensate for the signal loss. The slicer recovers the differential low-level signal to a CMOS-level single-ended signal,
for clock recovery and data re-timing.
Clock Recovery
The serial input data stream contains both data and clock. The clock recovery block is used to extract both data and clocks from this
input. In addition to data, two clocks of 62.5 MHz are recovered.
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PS8641
10/14/04