To enhance the processor IP cores Syntill8 offers a collection of optional peripheral interface IP blocks for use with the 8051 microcontroller IP. These include a Four-Wire Slave Interface (M4WIS), a Two-Wire Slave Interface (M2WIS) and a 1-Gigabit UDP/Ethernet MAC (UDPMAC) core.

The two-wire and four-wire slaves provide the complementary function to the integral two-wire and four-wire interfaces that are included in the standard M8051W and M8051EW cores. The UDPMAC provides an Ethernet MAC interface and UDP datagram interface to the M8051W and M8051EW using integral DMA and configurable packet FIFOs. The UDPMAC uses a standard RGMII interface to connect to an external PHY function.