CMSIS-Driver  Version 2.05
Peripheral Interface for Middleware and Application Code
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Ethernet Interface

Ethernet common definitions (Driver_ETH.h) More...


 Media Interface Types
 Ethernet Media Interface type.
 Ethernet MAC Interface
 Driver API for Ethernet MAC Peripheral (Driver_ETH_MAC.h)
 Ethernet PHY Interface
 Driver API for Ethernet PHY Peripheral (Driver_ETH_PHY.h)

Data Structures

 Ethernet MAC Address. More...


 Ethernet link state. More...


Ethernet common definitions (Driver_ETH.h)

Ethernet is a networking technology for exchanging data packages between computer systems. Several microcontrollers integrate an Ethernet MAC (Media Access Control) data-link layer that interfaces to an Ethernet PHY (Physical Interface Transceiver).

Wikipedia offers more information about the Ethernet.

Block Diagram**

The Ethernet PHY connects typically to the Ethernet MAC using an MII (Media Independent Interface) or RMII (Reduced Media Independent Interface).

Block Diagram of a typical Ethernet Interface

Ethernet API**

The following header files define the Application Programming Interface (API) for the Ethernet interface:

The driver implementation of the Ethernet MAC is a typical part of a Device Family Pack (DFP) that supports the peripherals of the microcontroller family. The driver implementation of the Ethernet PHY is a typical part of a Network Software Pack, since PHY is typically not integrated into the microcontroller.

For parameters, the value marked with (default) is the setting after the driver initialization.

Driver Functions**

The driver functions are published in the access struct as explained in Common Driver Functions

Both drivers are used in combination and usually the Ethernet MAC provides a media interface to the Ethernet PHY. A typical setup sequence for the drivers is shown below:

Example Code**

The following example code shows the usage of the Ethernet interface.

static ARM_DRIVER_ETH_MAC *mac;
static ARM_DRIVER_ETH_PHY *phy;
static ARM_ETH_MAC_ADDR own_mac_address;
static ARM_ETH_MAC_CAPABILITIES capabilities;
void ethernet_mac_notify (uint32_t event) {
switch (event) {
void initialize_ethernet_interface (void) {
mac = &Driver_ETH_MAC0;
phy = &Driver_ETH_PHY0;
// Initialize Media Access Controller
capabilities = mac->GetCapabilities ();
mac->Initialize (ethernet_mac_notify);
if (capabilities.mac_address == 0) {
// populate own_mac_address with the address to use
else {
// Initialize Physical Media Interface
if (phy->Initialize (mac->PHY_Read, mac->PHY_Write) == ARM_DRIVER_OK) {
phy->SetInterface (capabilities.media_interface);
static ARM_ETH_LINK_STATE ethernet_link; // current link status
void ethernet_check_link_status (void) {
link = phy->GetLinkState ();
if (link == ethernet_link) {
return; // link state unchanged
// link state changed
ethernet_link = link;
if (link == ARM_ETH_LINK_UP) { // start transfer
else { // stop transfer

Data Structure Documentation


Ethernet link information.

The Ethernet Link information provides parameters about the current established communication.

Returned by:

Data Fields
uint32_t speed: 2 Link speed: 0= 10 MBit, 1= 100 MBit, 2= 1 GBit.
uint32_t duplex: 1 Duplex mode: 0= Half, 1= Full.
uint32_t reserved: 29

Ethernet MAC Address.

Stores the MAC Address of the Ethernet interface as defined by IEEE 802. Wikipedia offers more information about the MAC Address.

Parameter for:

Data Fields
uint8_t b[6] MAC Address (6 bytes), MSB first.

Enumeration Type Documentation

Ethernet link state.

The Ethernet Link status shows if the communication is currently established (up) or interrupted (down).

Returned by:


Link is down.


Link is up.