1.1.3 EtherCAT LAN9255 Library
Ethernet for Control Automation Technology (EtherCAT) was developed by Beckhoff. EtherCAT is a fast and deterministic network, It processes data using dedicated hardware and software. It is based on a full duplex, manager(TwinCAT Manager)-client(LAN9255 Client) configuration.
EEPROM Emulation
In some system configurations the PDI (Processor Data Interface) is disabled, since much of the device is configured by the EEPROM contents. When EEPROM Emulation mode is used, the PDI configuration must be selected, as the EEPROM configuration data will be stored on the microcontroller’s internal memory. The microcontroller will configure the LAN9255 over the PDI interface and no external EEPROM device will be required to be connected to the LAN9255.
- Hardware Configuration:
EE_EMUL[2:0] PDI_SELECT 000 0x80 (SPI) 001 0x95 (HBI Indexed 16bit EtherCAT Direct Mapped) 010 0x91 (HBI Multiplexed 1 Phase 16-bit EtherCAT Direct Mapped) 011 0x93 (HBI Multiplexed 2 Phase 16-bit EtherCAT Direct Mapped) 100 0x82 (SPI EtherCAT Direct Mode) 101 0x05 (Beckhoff SPI Mode) 110 Unused 111 EEPROM is enabled - Software
Configuration:
Microchip provides ESF Demo code, which includes application files that support EEPROM Emulation, Configuration file (.xml) and Application file (.xlsx) are also provided.
From the EtherCAT host’s point of view, there is no difference between EEPROM Emulation mode and I2C EEPROM, the host just issues EEPROM commands and wait until the EEPROM interface is no longer busy.
Normally the ESI file that is loaded on the EEPROM, is generated using the SSC tool from Beckhoff. The EEPROM Emulation mode of the SSC tool must be configured for ESC EEPROM Emulation mode.
EEPROM Emulation Configurations Parameter Description ESC_EEPROM_EMULATION If set to 1, the EEPROM emulation is enabled and EEPROM commands are handled by the SSC. CREATE_EEPROM_CONTENT If set to 1, then a header file including the EEPROM data according to the client configuration will be created during the client file generation process. ESC_EEPROM_SIZE Available EEPROM buffer size in Bytes. EEPROM_READ_SIZE Number of Bytes the ESC can handle on a single read access. For LAN9255, this value is 0x08 EEPROM_WRITE_SIZE Number of Bytes the ESC can handle on a single write access. This value is always 2. For SSC tool EEPROM emulation ,select Hardware in Client Project Navigation Window and make sure ESC_EEPROM_SIZE is 0x800, ESC_EEPROM_EMULATION is 1 & CREATE_EEPROM_CONTENT is 0.
SSC tool EEPROM Configuration:
EtherCAT EEPROM Register Address Register Name 0x140 PDI Control Register 0x141 ESC Configuration Register 0x150 PDI Configuration Register 0x151 Sync/Latch PDI Configuration Register 0x982:0x983 Pulse Length of SyncSignals Register 0x152:0x153 PDI Extended Configuration Register 0x0012:0x0013 Configured Station Alias 0x0510:0x0511 MII Management Control/Status Register 0x0142:0x0143 ASIC Configuration Reserved 0x144:0x145 Reserved
Features Supported
- Supports the app_lan9255 EtherCAT Client Controller device.
- Supports EEPROM Emulation.
- Enables interfacing with different 32-bit microcontroller devices.
- Contains File over EtherCAT and Trigger & Counter demonstration applications.
- Demonstration applications are targeted for EVB-LAN9255-SAME53 Evaluation Board.
- Demonstration applications are configured to use the SSC Error LED feature. This
feature is implemented through the ERROR LED indicator on the board. When the
ERRRO LED is ON, this indicates either of the following conditions:
- EEPROM loading error
- EtherCAT client connectivity link failure
- Application Layer Event (AL Event) error indication
- EtherCAT State mode transition error indication
- The demonstration applications do not use the SSC Run LED feature.
- Driver supports SPI Indirect, SPI Direct and Beckhoff SPI mode of Process Data
Interface(PDI) selection.
Process Data Interface Mode EEPROM Source Data Config SPI/SQI Indirect Mode 0x80 SPI/SQI Direct Mode 0x82 The EEPROM Source Data config data in the above table should be specified in the ESC CONFIG DATA attribute in the
Microchip-SAME53-LAN9255-EtherCAT-Slave_SSC_Config_SPI_SQI_XXX_mode.xml file.
- FoE (File Over EtherCAT) can be used to download and upload a file to an EtherCAT device. Bank Switch algorithm is used to switch the new firmware downloaded.
- The LAN9255 SPI or SQI Client module provides a low pin count synchronous client
interface that facilitates communication between the LAN9255 and the
microcontroller. The SPI client provides the microcontroller access to the
LAN9255 System Control and Status Registers, internal FIFOs and memories.
The following is an overview of the functions provided by the LAN9255 SPI/SQI Client:
- Serial Read: 4-wire (clock, select, data in and data out) reads at up to 30 MHz Serial command, address and data. Single and multiple register reads with incrementing, decrementing or static addressing.
- Fast Read: 4-wire (clock, select, data in and data out) reads at up to 50 MHz Serial command, address and data. Dummy Byte(s) for first access. Single and multiple register reads with incrementing, decrementing or static addressing.
- The Beckhoff Client Stack Code supports different modes of synchronization which are based on three physical signals: (PDI_)IRQ, Sync0 and Sync1.Both SM-Synchron and Distributed Clocks (DC) synchronization are supported.
LAN9255 Firmware Overview
- drv_lan9255_ecat_util.c and drv_lan9255_ecat_util.h files are interfaced to Lan
9255 driver.
Name SPI Different Mode API Description ECAT_Initialization Initialize the hardware interface (SPI) used to communicate with Client Controller ECAT_Lan9255_IsPDIFunctional Verifies the hardware interface (SPI) is functional or not ECAT_Lan925x_SPIWrite Initiates an Indirect mode write transfer to Client Controller via selected PDI ECAT_Lan925x_SPIRead Initiates an Indirect mode read transfer to Client Controller via selected PDI ECAT_Lan925x_SPIFastRead Initiates an Indirect mode fast-read transfer to Client Controller via selected PDI ECAT_Lan925x_SPIReadPDRAM Initiates an Indirect mode read process data RAM transfer to Client Controller via selected PDI ECAT_Lan925x_SPIFastReadPDRAM Initiates an Indirect mode fast-read process data RAM transfer to Client Controller via selected PDI ECAT_Lan925x_SPIWritePDRAM Initiates an Indirect mode write process data RAM transfer to Client Controller via selected PDI ECAT_Lan9255_SPIWrite Initiates a direct mode write transfer to client Controller via selected PDI ECAT_Lan9255_SPIRead Initiates a direct mode read transfer to Client Controller via selected PDI ECAT_Lan9255_SPIFastRead Initiates a direct mode fast-read transfer to Client Controller via selected PDI ECAT_Lan9255_Beckhoff_SPIWrite Initiates a Beckhoff mode write transfer to Client Controller via selected PDI ECAT_Lan9255_Beckhoff_SPIRead Initiates a Beckhoff mode read transfer to Client Controller via selected PDI ECAT_ESCIRQInitialization Interrupt service routine initialization for the interrupt from EtherCAT Client Controller ECAT_SyncInterruptsInitialization Sync0 and Sync1 Interrupt service routine Initialization Name SQI Different Mode API Description ECAT_Lan925x_SQIWrite Initiates an Indirect mode or Direct Mode SQI write transfer to Client Controller via selected PDI ECAT_Lan925x_SQIRead Initiates an Indirect mode or Direct Mode SQI read transfer to Client Controller via selected PDI ECAT_LAN925x_SQIWritePDRAM Initiates an Indirect mode SQI write process to Client Controller via selected PDI ECAT_Lan925x_SQIReadPDRAM Initiates an Indirect mode SQI read process data RAM transfer to Client Controller via selected PDI