VSC8486

The VSC8486 is a LAN/WAN XAUI or XGMII transceiver that converts 3 Gbps XAUI data to a 10 Gbps serial stream. At just 750 mW, the VSC8486 is ideal for applications requiring low power. The device is also equipped with an additional full-rate data port that can be utilized for bypass monitoring or channel monitoring applications. The device meets all specifications for 10 Gigabit Ethernet (GbE) Layer-1 processing, as defined in IEEE 802.3ae.

The VSC8486 offers exceptional 10 Gbps mixed-signal performance with a data output that features programmable pre-emphasis to enable longer traces of copper. The VSC8486 high-speed serial I/O supports 9.9 Gbps, 10.3 Gbps, and 10.5 Gbps, as defined by IEEE 802.3ae and T11 10 GFC, and is fully compliant with the SONET jitter specification defined by Bellcore GR253.

There are four main data processing blocks in the device: XGXS, PCS,WIS, and PMA. The 10 GbE extender sublayer (XGXS) accepts 8b/10b data running at 3.125 Gbps and decodes it for transmission to the physical coding sublayer (PCS). The XGXS is capable of deskewing more than 60 bit times between lanes. The PCS receives data from the XGXS at 10 Gbps and encodes data according to the 64b/66b algorithm described in IEEE 802.3ae clause 49.

The PCS features an optional extended mode (E-PCS) that also runs at the 64b/66b rate. This extended mode uses an alternative framing algorithm that adds forward error correction (FEC) to provide ~2.5 dB of net electrical coding gain. The E-PCS is available for LAN mode but not WAN mode.

The PCS outputs data to the WAN interface sublayer (WIS). (This mode is bypassed in LAN mode.) The WIS optionally takes data from the PCS at 9.953 Gbps and frames data in a SONET STS-192c frame, as described in IEEE 802.3ae clause 50. Additionally, the WIS block contains extended SONET and SDH processing capabilities that allow system operators to leverage valuable performance monitoring data. Finally, data is delivered to the physical media attachment (PMA) block. The PMA multiplexes the internal parallel data bus into a 10 Gbps data stream.

The 10 Gbps to XAUI data channel performs the operations described above in reverse. Notable features in this path are a SONET-compliant LOS detector and a 10 Gbps receiver that is fully compliant with XFI specifications, including stressed eye criteria.

The device operates using a 1.2 V supply dissipating only 700 mW in LAN mode and 750 mW in WAN mode. The VSC8486 is available in standard and lead(Pb)-free (second-level interconnect only) packages, measuring 17 mm × 17 mm with 256 pins and 1.0 mm pin pitch.