Ethernet Interface

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

Content
	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
struct	ARM_ETH_LINK_INFO
	Ethernet link information. More...
struct	ARM_ETH_MAC_ADDR
	Ethernet MAC Address. More...

Enumerations
enum	ARM_ETH_LINK_STATE {   ARM_ETH_LINK_DOWN,   ARM_ETH_LINK_UP }
	Ethernet link state. More...

Description

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:

• Driver_ETH.h : Common definitions of the Ethernet PHY and MAC part
• Driver_ETH_MAC.h : API for the Ethernet MAC
• Driver_ETH_PHY.h : API for the Ethernet PHY

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.

Note

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

• ARM_DRIVER_ETH_MAC : access struct for Ethernet MAC driver functions.
• ARM_DRIVER_ETH_PHY : access struct for Ethernet PHY 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.

extern ARM_DRIVER_ETH_MAC Driver_ETH_MAC0;
extern ARM_DRIVER_ETH_PHY Driver_ETH_PHY0;
 
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);
  mac->PowerControl (ARM_POWER_FULL);
 
  if (capabilities.mac_address == 0)  {
    // populate own_mac_address with the address to use
    mac->SetMacAddress(&own_mac_address);
  }
  else {
    mac->GetMacAddress(&own_mac_address);
  }
 
  // Initialize Physical Media Interface
  if (phy->Initialize (mac->PHY_Read, mac->PHY_Write) == ARM_DRIVER_OK) {
    phy->PowerControl (ARM_POWER_FULL);
    phy->SetInterface (capabilities.media_interface);
    phy->SetMode (ARM_ETH_PHY_AUTO_NEGOTIATE);
  }
    :
    :
}
 
 
static ARM_ETH_LINK_STATE ethernet_link;   // current link status
 
void ethernet_check_link_status (void) {
  ARM_ETH_LINK_STATE link;
 
  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
    ARM_ETH_LINK_INFO info = phy->GetLinkInfo ();
    mac->Control(ARM_ETH_MAC_CONFIGURE,
                 info.speed  << ARM_ETH_MAC_SPEED_Pos  |
                 info.duplex << ARM_ETH_MAC_DUPLEX_Pos |
                 ARM_ETH_MAC_ADDRESS_BROADCAST);
    mac->Control(ARM_ETH_MAC_CONTROL_TX, 1);
    mac->Control(ARM_ETH_MAC_CONTROL_RX, 1);
  }
  else {                                   // stop transfer
    mac->Control(ARM_ETH_MAC_FLUSH, ARM_ETH_MAC_FLUSH_TX | ARM_ETH_MAC_FLUSH_RX);
    mac->Control(ARM_ETH_MAC_CONTROL_TX, 0);
    mac->Control(ARM_ETH_MAC_CONTROL_RX, 0);
  }
}

---

Data Structure Documentation

struct ARM_ETH_LINK_INFO

Ethernet link information.

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

Returned by:

• ARM_ETH_PHY_GetLinkInfo

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

struct ARM_ETH_MAC_ADDR

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:

• ARM_ETH_MAC_GetMacAddress, ARM_ETH_MAC_SetMacAddress, ARM_ETH_MAC_SetAddressFilter

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

Enumeration Type Documentation

enum ARM_ETH_LINK_STATE

Ethernet link state.

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

Returned by:

• ARM_ETH_PHY_GetLinkState

Enumerator
ARM_ETH_LINK_DOWN	Link is down.
ARM_ETH_LINK_UP	Link is up.