4 channel SERDES operating at up to 6.25Gbps for XAUI, RXAUI and SGMII (40nm TSMC)

PSI6254XRX is a 4 channel SERDES capable of providing XAUI (10G Attachment Unit Interface), RXAUI (10G Reduced Attachment Unit Interface) and SGMII interfaces. Fig. 1 shows the top-level block diagram of this module in the XAUI mode where these 4 channels can receive and transmit data at the rate of 3.125Gbps each. The eye diagram at the TX output in the XAUI mode is shown in Fig. 2. Fig. 3 shows the top-level block diagram of the module in RXAUI mode where 2 channels are disabled and the other 2 operate at the rate of 6.25Gbps each. The eye diagram in the RXAUI mode is shown in Fig. 4. The 4 channels can also operate as 4 independent channels. Depending on the application, each transmitter can serialize 8, 10, 16 or 20 bit parallel data to a differential serial output and each receiver can de-serialize a differential serial input to 8, 10, 16 or 20 bit parallel output. A common block including a TXPLL provides clocks to the serializers in all channels. To improve signal integrity the common block also includes a calibration circuit providing control signals to make the transmitter output resistance and the receiver input resistance within 50Ω±5%.