Connect Ethernet controller with PIC Code




The ENC28J60 is a stand-alone Ethernet controller with an industry standard Serial Peripheral Interface (SPI). It is designed to serve as an Ethernet network interface for any controller equipped with SPI.
The ENC28J60 meets all of the IEEE 802.3 specifications. It incorporates a number of packet filtering schemes to limit incoming packets. It also provides an internal DMA module for fast data throughput and hardware assisted IP checksum calculations. Communication with the host controller is implemented via two interrupt pins and the SPI, with data rates of up to 10 Mb/s. Two dedicated pins are used for LED link and network activity indication.
This library is designed to simplify handling of the underlying hardware (ENC28J60). It works with any PIC with integrated SPI and more than 4 Kb ROM memory. 38 to 40 MHz clock is recommended to get from 8 to 10 Mhz SPI clock, otherwise PIC should be clocked by ENC28J60 clock output due to its silicon bug in SPI hardware. If you try lower PIC clock speed, there might be board hang or miss some requests.
SPI Ethernet ENC28J60 Library supports:

  • IPv4 protocol.
  • ARP requests.
  • ICMP echo requests.
  • UDP requests.
  • TCP requests (no stack, no packet reconstruction).
  • ARP client with cache.
  • DNS client.
  • UDP client.
  • DHCP client.
  • packet fragmentation is NOT supported.

  Important :

  • Due to PIC16 RAM/Flash limitations PIC16 library does NOT have ARP, DNS, UDP and DHCP client support implemented.
  • Global library variable SPI_Ethernet_userTimerSec is used to keep track of time for all client implementations (ARP, DNS, UDP and DHCP). It is user responsibility to increment this variable each second in it’s code if any of the clients is used.
  • For advanced users there are header files ("__EthEnc28j60.h" and "__EthEnc28j60Private.h") in Uses\P16 and Uses\P18 folders of the compiler with description of all routines and global variables, relevant to the user, implemented in the SPI Ethernet ENC28J60 Library.
  • The appropriate hardware SPI module must be initialized before using any of the SPI Ethernet ENC28J60 library routines.
  • For MCUs with two SPI modules it is possible to initialize both of them and then switch by using the SPI_Set_Active() routine.Connect Ethernet controller with PIC Code

Library Dependency Tree

External dependencies of SPI Ethernet ENC28J60 Library

The following variables must be defined in all projects using SPI Ethernet ENC28J60 Library: Description: Examples :
extern sfr sbit SPI_Ethernet_CS; ENC28J60 chip select pin. sbit SPI_Ethernet_CS at RC1_bit;
extern sfr sbit SPI_Ethernet_RST; ENC28J60 reset pin. sbit SPI_Ethernet_Rst at RC0_bit;
extern sfr sbit SPI_Ethernet_CS_Direction; Direction of the ENC28J60 chip select pin. sbit SPI_Ethernet_CS_Direction at TRISC1_bit;
extern sfr sbit SPI_Ethernet_RST_Direction; Direction of the ENC28J60 reset pin. sbit SPI_Ethernet_Rst_Direction at TRISC0_bit;
The following routines must be defined in all project using SPI Ethernet ENC28J60 Library: Description: Examples :
unsigned int SPI_Ethernet_UserTCP(unsigned char *remoteHost, unsigned int remotePort, unsigned int localPort, unsigned int reqLength, TEthPktFlags *flags); TCP request handler. Refer to the library example at the bottom of this page for code implementation.
unsigned int SPI_Ethernet_UserUDP(unsigned char *remoteHost, unsigned int remotePort, unsigned int localPort, unsigned int reqLength, TEthPktFlags *flags); UDP request handler. Refer to the library example at the bottom of this page for code implementation.

Library Routines

PIC16 and PIC18:

  • SPI_Ethernet_Init
  • SPI_Ethernet_Enable
  • SPI_Ethernet_Disable
  • SPI_Ethernet_doPacket
  • SPI_Ethernet_putByte
  • SPI_Ethernet_putBytes
  • SPI_Ethernet_putString
  • SPI_Ethernet_putConstString
  • SPI_Ethernet_putConstBytes
  • SPI_Ethernet_getByte
  • SPI_Ethernet_getBytes
  • SPI_Ethernet_UserTCP
  • SPI_Ethernet_UserUDP

PIC18 Only:

  • SPI_Ethernet_getIpAddress
  • SPI_Ethernet_getGwIpAddress
  • SPI_Ethernet_getDnsIpAddress
  • SPI_Ethernet_getIpMask
  • SPI_Ethernet_confNetwork
  • SPI_Ethernet_arpResolve
  • SPI_Ethernet_sendUDP
  • SPI_Ethernet_dnsResolve
  • SPI_Ethernet_initDHCP
  • SPI_Ethernet_doDHCPLeaseTime
  • SPI_Ethernet_renewDHCP

SPI_Ethernet_Init

Prototype void SPI_Ethernet_Init(unsigned char *mac, unsigned char *ip, unsigned char fullDuplex);
Returns Nothing.
Description This is MAC module routine. It initializes ENC28J60 controller. This function is internaly splited into 2 parts to help linker when coming short of memory.
ENC28J60 controller settings (parameters not mentioned here are set to default):

  • receive buffer start address : 0x0000.
  • receive buffer end address : 0x19AD.
  • transmit buffer start address: 0x19AE.
  • transmit buffer end address : 0x1FFF.
  • RAM buffer read/write pointers in auto-increment mode.
  • receive filters set to default: CRC + MAC Unicast + MAC Broadcast in OR mode.
  • flow control with TX and RX pause frames in full duplex mode.
  • frames are padded to 60 bytes + CRC.
  • maximum packet size is set to 1518.
  • Back-to-Back Inter-Packet Gap: 0x15 in full duplex mode; 0x12 in half duplex mode.
  • Non-Back-to-Back Inter-Packet Gap: 0x0012 in full duplex mode; 0x0C12 in half duplex mode.
  • Collision window is set to 63 in half duplex mode to accomodate some ENC28J60 revisions silicon bugs.
  • CLKOUT output is disabled to reduce EMI generation.
  • half duplex loopback disabled.
  • LED configuration: default (LEDA-link status, LEDB-link activity).

Parameters:

  • mac: RAM buffer containing valid MAC address.
  • ip: RAM buffer containing valid IP address.
  • fullDuplex: ethernet duplex mode switch. Valid values: 0 (half duplex mode) and 1 (full duplex mode).
Requires Global variables :

  • SPI_Ethernet_CS: Chip Select line
  • SPI_Ethernet_CS_Direction: Direction of the Chip Select pin
  • SPI_Ethernet_RST: Reset line
  • SPI_Ethernet_RST_Direction: Direction of the Reset pin

must be defined before using this function.
The SPI module needs to be initialized. See the SPIx_Init and SPIx_Init_Advanced routines.

Example
#define SPI_Ethernet_HALFDUPLEX     0
#define SPI_Ethernet_FULLDUPLEX     1

// mE ethernet NIC pinout
sfr sbit SPI_Ethernet_Rst at RC0_bit;
sfr sbit SPI_Ethernet_CS  at RC1_bit;
sfr sbit SPI_Ethernet_Rst_Direction at TRISC0_bit;
sfr sbit SPI_Ethernet_CS_Direction  at TRISC1_bit;
// end ethernet NIC definitions

unsigned char myMacAddr[6] = {0x00, 0x14, 0xA5, 0x76, 0x19, 0x3f}; // my MAC address 
unsigned char myIpAddr     = {192, 168,   1, 60 };  // my IP addr

SPI1_Init(); 
SPI_Ethernet_Init(myMacAddr, myIpAddr, SPI_Ethernet_FULLDUPLEX);

SPI_Ethernet_Enable

Prototype void SPI_Ethernet_Enable(unsigned char enFlt);
Returns Nothing.
Description This is MAC module routine. This routine enables appropriate network traffic on the ENC28J60 module by the means of it’s receive filters (unicast, multicast, broadcast, crc). Specific type of network traffic will be enabled if a corresponding bit of this routine’s input parameter is set. Therefore, more than one type of network traffic can be enabled at the same time. For this purpose, predefined library constants (see the table below) can be ORed to form appropriate input value.
Parameters:

  • enFlt: network traffic/receive filter flags. Each bit corresponds to the appropriate network traffic/receive filter:
    Bit Mask Description Predefined library const
    0 0x01 MAC Broadcast traffic/receive filter flag. When set, MAC broadcast traffic will be enabled. _SPI_Ethernet_BROADCAST
    1 0x02 MAC Multicast traffic/receive filter flag. When set, MAC multicast traffic will be enabled. _SPI_Ethernet_MULTICAST
    2 0x04 not used none
    3 0x08 not used none
    4 0x10 not used none
    5 0x20 CRC check flag. When set, packets with invalid CRC field will be discarded. _SPI_Ethernet_CRC
    6 0x40 not used none
    7 0x80 MAC Unicast traffic/receive filter flag. When set, MAC unicast traffic will be enabled. _SPI_Ethernet_UNICAST

      Note :

    • Advanced filtering available in the ENC28J60 module such as Pattern Match, Magic Packet and Hash Table can not be enabled by this routine. Additionaly, all filters, except CRC, enabled with this routine will work in OR mode, which means that packet will be received if any of the enabled filters accepts it.
    • This routine will change receive filter configuration on-the-fly. It will not, in any way, mess with enabling/disabling receive/transmit logic or any other part of the ENC28J60 module. The ENC28J60 module should be properly cofigured by the means of SPI_Ethernet_Init routine.
Requires Ethernet module has to be initialized. See SPI_Ethernet_Init.
Example
SPI_Ethernet_Enable(_SPI_Ethernet_CRC | _SPI_Ethernet_UNICAST); // enable CRC checking and Unicast traffic

SPI_Ethernet_Disable

Prototype void SPI_Ethernet_Disable(unsigned char disFlt);
Returns Nothing.
Description This is MAC module routine. This routine disables appropriate network traffic on the ENC28J60 module by the means of it’s receive filters (unicast, multicast, broadcast, crc). Specific type of network traffic will be disabled if a corresponding bit of this routine’s input parameter is set. Therefore, more than one type of network traffic can be disabled at the same time. For this purpose, predefined library constants (see the table below) can be ORed to form appropriate input value.
Parameters:

  • disFlt: network traffic/receive filter flags. Each bit corresponds to the appropriate network traffic/receive filter:
    Bit Mask Description Predefined library const
    0 0x01 MAC Broadcast traffic/receive filter flag. When set, MAC broadcast traffic will be disabled. _SPI_Ethernet_BROADCAST
    1 0x02 MAC Multicast traffic/receive filter flag. When set, MAC multicast traffic will be disabled. _SPI_Ethernet_MULTICAST
    2 0x04 not used none
    3 0x08 not used none
    4 0x10 not used none
    5 0x20 CRC check flag. When set, CRC check will be disabled and packets with invalid CRC field will be accepted. _SPI_Ethernet_CRC
    6 0x40 not used none
    7 0x80 MAC Unicast traffic/receive filter flag. When set, MAC unicast traffic will be disabled. _SPI_Ethernet_UNICAST

      Note :

    • Advanced filtering available in the ENC28J60 module such as Pattern Match, Magic Packet and Hash Table can not be disabled by this routine.
    • This routine will change receive filter configuration on-the-fly. It will not, in any way, mess with enabling/disabling receive/transmit logic or any other part of the ENC28J60 module.
    • The ENC28J60 module should be properly cofigured by the means of SPI_Ethernet_Init routine.
Requires Ethernet module has to be initialized.
Example
SPI_Ethernet_Disable(_SPI_Ethernet_CRC | _SPI_Ethernet_UNICAST); // disable CRC checking and Unicast traffic

SPI_Ethernet_doPacket

Prototype unsigned char SPI_Ethernet_doPacket();
Returns
  • 0 – upon successful packet processing (zero packets received or received packet processed successfully).
  • 1 – upon reception error or receive buffer corruption. ENC28J60 controller needs to be restarted.
  • 2 – received packet was not sent to us (not our IP, nor IP broadcast address).
  • 3 – received IP packet was not IPv4.
  • 4 – received packet was of type unknown to the library.
Description This is MAC module routine. It processes next received packet if such exists. Packets are processed in the following manner:

  • ARP & ICMP requests are replied automatically.
  • upon TCP request the SPI_Ethernet_UserTCP function is called for further processing.
  • upon UDP request the SPI_Ethernet_UserUDP function is called for further processing.
  Note : SPI_Ethernet_doPacket must be called as often as possible in user’s code.
Requires Ethernet module has to be initialized.
Example
if (SPI_Ethernet_doPacket() == 0)(1) {  // process received packets
  ...
}

SPI_Ethernet_putByte

Prototype void SPI_Ethernet_putByte(unsigned char v);
Returns Nothing.
Description This is MAC module routine. It stores one byte to address pointed by the current ENC28J60 write pointer (EWRPT).
Parameters:

  • v: value to store
Requires Ethernet module has to be initialized.
Example
char data_;
...
SPI_Ethernet_putByte(data); // put an byte into ENC28J60 buffer

SPI_Ethernet_putBytes

Prototype void SPI_Ethernet_putBytes(unsigned char *ptr, unsigned int n);
Returns Nothing.
Description This is MAC module routine. It stores requested number of bytes into ENC28J60 RAM starting from current ENC28J60 write pointer (EWRPT) location.
Parameters:

  • ptr: RAM buffer containing bytes to be written into ENC28J60 RAM.
  • n: number of bytes to be written.
Requires Ethernet module has to be initialized.
Example
char *buffer =  "mikroElektronika";  
...
SPI_Ethernet_putBytes(buffer, 16); // put an RAM array into ENC28J60 buffer

SPI_Ethernet_putConstBytes

Prototype void SPI_Ethernet_putConstBytes(const unsigned char *ptr, unsigned int n);
Returns Nothing.
Description This is MAC module routine. It stores requested number of const bytes into ENC28J60 RAM starting from current ENC28J60 write pointer (EWRPT) location.
Parameters:

  • ptr: const buffer containing bytes to be written into ENC28J60 RAM.
  • n: number of bytes to be written.
Requires Ethernet module has to be initialized.
Example
const char *buffer =  "mikroElektronika";  
...
SPI_Ethernet_putConstBytes(buffer, 16); // put a const array into ENC28J60 buffer

SPI_Ethernet_putString

Prototype unsigned int SPI_Ethernet_putString(unsigned char *ptr);
Returns Number of bytes written into ENC28J60 RAM.
Description This is MAC module routine. It stores whole string (excluding null termination) into ENC28J60 RAM starting from current ENC28J60 write pointer (EWRPT) location.
Parameters:

  • ptr: string to be written into ENC28J60 RAM.
Requires Ethernet module has to be initialized.
Example
char *buffer =  "mikroElektronika";  
...
SPI_Ethernet_putString(buffer); // put a RAM string into ENC28J60 buffer

SPI_Ethernet_putConstString

Prototype unsigned int SPI_Ethernet_putConstString(const unsigned char *ptr);
Returns Number of bytes written into ENC28J60 RAM.
Description This is MAC module routine. It stores whole const string (excluding null termination) into ENC28J60 RAM starting from current ENC28J60 write pointer (EWRPT) location.
Parameters:

  • ptr: const string to be written into ENC28J60 RAM.
Requires Ethernet module has to be initialized.
Example
const char *buffer =  "mikroElektronika"; 
...
SPI_Ethernet_putConstString(buffer); // put a const string into ENC28J60 buffer

SPI_Ethernet_getByte

Prototype unsigned char SPI_Ethernet_getByte();
Returns Byte read from ENC28J60 RAM.
Description This is MAC module routine. It fetches a byte from address pointed to by current ENC28J60 read pointer (ERDPT).
Requires Ethernet module has to be initialized.
Example
char buffer; 
...
buffer = SPI_Ethernet_getByte(); // read a byte from ENC28J60 buffer

SPI_Ethernet_getBytes

Prototype void SPI_Ethernet_getBytes(unsigned char *ptr, unsigned int addr, unsigned int n);
Returns Nothing.
Description This is MAC module routine. It fetches equested number of bytes from ENC28J60 RAM starting from given address. If value of 0xFFFF is passed as the address parameter, the reading will start from current ENC28J60 read pointer (ERDPT) location.
Parameters:

  • ptr: buffer for storing bytes read from ENC28J60 RAM.
  • addr: ENC28J60 RAM start address. Valid values: 0..8192.
  • n: number of bytes to be read.
Requires Ethernet module has to be initialized.
Example
char buffer[16];  
...
SPI_Ethernet_getBytes(buffer, 0x100, 16); // read 16 bytes, starting from address 0x100

SPI_Ethernet_UserTCP

Prototype unsigned int SPI_Ethernet_UserTCP(unsigned char *remoteHost, unsigned int remotePort, unsigned int localPort, unsigned int reqLength, TEthPktFlags *flags);
Returns
  • 0 – there should not be a reply to the request.
  • Length of TCP/HTTP reply data field – otherwise.
Description This is TCP module routine. It is internally called by the library. The user accesses to the TCP/HTTP request by using some of the SPI_Ethernet_get routines. The user puts data in the transmit buffer by using some of the SPI_Ethernet_put routines. The function must return the length in bytes of the TCP/HTTP reply, or 0 if there is nothing to transmit. If there is no need to reply to the TCP/HTTP requests, just define this function with return(0) as a single statement.
Parameters:

  • remoteHost: client’s IP address.
  • remotePort: client’s TCP port.
  • localPort: port to which the request is sent.
  • reqLength: TCP/HTTP request data field length.
  • flags: structure consisted of two bit fields :
    typedef struct {
      unsigned canCloseTCP: 1;  // flag which closes socket
      unsigned isBroadcast: 1;  // flag which denotes that the IP package has been received via subnet broadcast address (not used for PIC16 family)
    } TEthPktFlags;
    
  Note : The function source code is provided with appropriate example projects. The code should be adjusted by the user to achieve desired reply.
Requires Ethernet module has to be initialized.
Example This function is internally called by the library and should not be called by the user’s code.

SPI_Ethernet_UserUDP

Prototype unsigned int SPI_Ethernet_UserUDP(unsigned char *remoteHost, unsigned int remotePort, unsigned int destPort, unsigned int reqLength, TEthPktFlags *flags);
Returns
  • 0 – there should not be a reply to the request.
  • Length of UDP reply data field – otherwise.
Description This is UDP module routine. It is internally called by the library. The user accesses to the UDP request by using some of the SPI_Ethernet_get routines. The user puts data in the transmit buffer by using some of the SPI_Ethernet_put routines. The function must return the length in bytes of the UDP reply, or 0 if nothing to transmit. If you don’t need to reply to the UDP requests, just define this function with a return(0) as single statement.
Parameters:

  • remoteHost: client’s IP address.
  • remotePort: client’s port.
  • destPort: port to which the request is sent.
  • flags: structure consisted of two bit fields :
    typedef struct {
      unsigned canCloseTCP: 1;  // flag which closes TCP socket (not relevant to UDP)
      unsigned isBroadcast: 1;  // flag which denotes that the IP package has been received via subnet broadcast address (not used for PIC16 family)
    } TEthPktFlags;
    
      Note : The function source code is provided with appropriate example projects. The code should be adjusted by the user to achieve desired reply.
Requires Ethernet module has to be initialized.
Example This function is internally called by the library and should not be called by the user’s code.

SPI_Ethernet_getIpAddress

Prototype unsigned char * SPI_Ethernet_getIpAddress();
Returns Pointer to the global variable holding IP address.
Description This routine should be used when DHCP server is present on the network to fetch assigned IP address.

  Note : User should always copy the IP address from the RAM location returned by this routine into it’s own IP address buffer. These locations should not be altered by the user in any case!
Requires Ethernet module has to be initialized.
Available for PIC18 family MCUs only.
Example
unsigned char ipAddr[4];  // user IP address buffer
... 
memcpy(ipAddr, SPI_Ethernet_getIpAddress(), 4); // fetch IP address

SPI_Ethernet_getGwIpAddress

Prototype unsigned char * SPI_Ethernet_getGwIpAddress();
Returns Pointer to the global variable holding gateway IP address.
Description This routine should be used when DHCP server is present on the network to fetch assigned gateway IP address.

  Note : User should always copy the IP address from the RAM location returned by this routine into it’s own gateway IP address buffer. These locations should not be altered by the user in any case!
Requires Ethernet module has to be initialized.
Available for PIC18 family MCUs only.
Example
unsigned char gwIpAddr[4];  // user gateway IP address buffer
... 
memcpy(gwIpAddr, SPI_Ethernet_getGwIpAddress(), 4); // fetch gateway IP address 

SPI_Ethernet_getDnsIpAddress

Prototype unsigned char * SPI_Ethernet_getDnsIpAddress()
Returns Pointer to the global variable holding DNS IP address.
Description his routine should be used when DHCP server is present on the network to fetch assigned DNS IP address.

  Note : User should always copy the IP address from the RAM location returned by this routine into it’s own DNS IP address buffer. These locations should not be altered by the user in any case!
Requires Ethernet module has to be initialized.
Available for PIC18 family MCUs only.
Example
unsigned char dnsIpAddr[4];  // user DNS IP address buffer
... 
memcpy(dnsIpAddr, SPI_Ethernet_getDnsIpAddress(), 4); // fetch DNS server address 

Connect Ethernet controller with PIC Code schematich

SPI_Ethernet_getIpMask

Prototype unsigned char * SPI_Ethernet_getIpMask()
Returns Pointer to the global variable holding IP subnet mask.
Description This routine should be used when DHCP server is present on the network to fetch assigned IP subnet mask.

  Note : User should always copy the IP address from the RAM location returned by this routine into it’s own IP subnet mask buffer. These locations should not be altered by the user in any case!
Requires Ethernet module has to be initialized.
Available for PIC18 family MCUs only.
Example
unsigned char IpMask[4];  // user IP subnet mask buffer
... 
memcpy(IpMask, SPI_Ethernet_getIpMask(), 4); // fetch IP subnet mask

SPI_Ethernet_confNetwork

Prototype void SPI_Ethernet_confNetwork(char *ipMask, char *gwIpAddr, char *dnsIpAddr);
Returns Nothing.
Description Configures network parameters (IP subnet mask, gateway IP address, DNS IP address) when DHCP is not used.
Parameters:

  • ipMask: IP subnet mask.
  • gwIpAddr gateway IP address.
  • dnsIpAddr: DNS IP address.

 

 

For more detail: Connect Ethernet controller with PIC Code




Current Project / Post can also be found using:

  • ethernet pic
  • SPI_Ethernet_UserUDP

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