The KSZ 8851 family is pin compatible to the KSZ8841 and KSZ8842 family. The devices also include an 8-, 16- or 32-bit generic host, and SPI interface. Performance is 80Mbps or higher, which is a significantly better than the 8841 and 8842. The buffer memory (or SRAM size)  is 18k, split between 12k on the receipt side and 6k on the transmit side. Some of the unique features are that it supports both big-endian and little-endian processors. It supports tcp/udp/icmp/ipv4 v6 checksum generation and correction in the hardware. Also added is an enhanced power management feature. Programmable I/O options are available, which allow customers to use 1.8, 2.5 or 3.5 I/Os with this device. Package options include: 128-pin PQFP, 48-pin TQFP, and 32-pin MLF and industrial temperature options are available as well.