RJ203A+EM203A – TIBBO

The RJ203A+EM203A is a two-chip embedded Ethernet solution from Texas Instruments, comprising the RJ203A Ethernet PHY and the EM203A Ethernet MAC controller. The RJ203A is a 10/100Base-TX physical layer transceiver compliant with IEEE 802.3 standards, supporting auto-negotiation and auto-MDIX functionality for simplified network connectivity. It interfaces with the EM203A via a standard Media Independent Interface (MII) or Reduced MII (RMII). The EM203A provides the media access control layer, handling Ethernet frame processing, address filtering, and collision detection. This chipset implements the TIBBO/11+ protocol stack, enabling TCP/IP communication and higher-level application protocols. The combined solution is RoHS compliant, indicating adherence to Restriction of Hazardous Substances directives for environmental safety. The EM203A typically interfaces with a microcontroller via a parallel bus or SPI interface for data transfer and control.