Ethernet Library

PIC32MX family of microcontrollers feature an embedded Ethernet controller module. The Ethernet controller is a bus master module that interfaces with an off-chip Physical Layer (PHY) to implement a complete Ethernet node in a system.

It provides the modules needed to implement a 10/100 Mbps Ethernet node using an external PHY chip. In order to offload the CPU from moving packet data to and from the module, internal descriptor-based DMA engines are included in the controller.

The Ethernet Controller consists of the following modules:

Media Access Control (MAC) block:
Responsible for implementing the MAC functions of the Ethernet specification.
Flow Control (FC) block :
Responsible for control of the transmission of PAUSE frames. Reception of PAUSE frames is handled within the MAC.
RX Filter (RXF) block :
This module performs filtering on every receive packet to determine whether each packet should be accepted or rejected.
TX DMA/TX BM Engine :
The TX DMA and TX Buffer Management engines perform data transfers from the memory (using descriptor tables) to the MAC Transmit Interface.
RX DMA/RX BM Engine :
The RX DMA and RX Buffer Management engines transfer receive packets from the MAC to the memory (using descriptor tables).

Ethernet library supports :

Supports 10/100 Mbps data transfer rates.
Supports full-duplex and half-duplex operation.
Supports RMII and MII PHY interface.
Supports MIIM PHY management interface.
Supports both manual and automatic flow control.
RAM descriptor-based DMA operation for both receive and transmit path.
Fully configurable interrupts.
Configurable receive packet filtering :
- CRC check.
- 64-byte pattern match.
- Broadcast, multicast and unicast packets.
- Magic Packet.
- 64-bit hash table.
- Runt packet.
Supports packet payload checksum calculation
Supports various hardware statistics counters

Important :

By default, the Ethernet library implementation initializes the PHY SMSC 8720A chip (present on the mikroElektronika's MultiMedia Board for PIC32MX7).
Global library variable 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 is __EthernetPrivate.mbas unit in Uses folder of the compiler with description of all routines and global variables, relevant to the user, implemented in the Ethernet Library.

Library Routines

Ethernet_Init
Ethernet_SetPHYInit
Ethernet_Set_Default_PHY
Ethernet_Enable
Ethernet_Disable
Ethernet_doPacket
Ethernet_putByte
Ethernet_putBytes
Ethernet_putString
Ethernet_putConstString
Ethernet_putConstBytes
Ethernet_getByte
Ethernet_getBytes
Ethernet_UserTCP
Ethernet_UserUDP
Ethernet_getIpAddress
Ethernet_getGwIpAddress
Ethernet_getDnsIpAddress
Ethernet_getIpMask
Ethernet_confNetwork
Ethernet_arpResolve
Ethernet_sendUDP
Ethernet_dnsResolve
Ethernet_initDHCP
Ethernet_doDHCPLeaseTime
Ethernet_renewDHCP

Ethernet_Init

Prototype	sub procedure Ethernet_Init(dim byref mac as byte, dim byref ip as byte, dim fullDuplex as longword)
Returns	Nothing.
Description	This is MAC module routine. It initializes Ethernet controller. This function is internaly splited into 2 parts to help linker when coming short of memory. Ethernet controller settings (parameters not mentioned here are set to default): 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. maximum packet size is set to `1536`. 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. 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. `configuration:` ethernet duplex mode switch. Valid values: `_ETHERNET_HALFDUPLEX` `_ETHERNET_FULLDUPLEX` `_ETHERNET_SPEED_10` `_ETHERNET_SPEED_100` `_ETHERNET_DEFAULT_MAC` - if this flag is used, default MAC address written in the MCU is used `_ETHERNET_CUSTOM_MAC` - if this flag is used, the MAC address in the routine is used `_ETHERNET_AUTO_NEGOTIATION` `_ETHERNET_MANUAL_NEGOTIATION` Note : If a DHCP server is to be used, IP address should be set to `0.0.0.0`.
Requires	Nothing.
Example	dim myMacAddr as byte[6] ' my MAC address myIpAddr as byte[4] ' my IP addr ... myMacAddr[0] = 0x00 myMacAddr[1] = 0x14 myMacAddr[2] = 0xA5 myMacAddr[3] = 0x76 myMacAddr[4] = 0x19 myMacAddr[5] = 0x3F myIpAddr[0] = 192 myIpAddr[1] = 168 myIpAddr[2] = 20 myIpAddr[3] = 60 Ethernet_Init(myMacAddr, myIpAddr, _ETHERNET_AUTO_NEGOTIATION)

Ethernet_SetPHYInit

Prototype	sub procedure Ethernet_SetPHYInit(PHYInit_ptr : ^TEthernet_PHYInit_Ptr)
Returns	Nothing.
Description	By default, the Ethernet library implementation initializes the PHY SMSC 8720A chip (present on the mikroElektronika's MultiMedia Board for PIC32MX7). If the user wants initialization for some other PHY module, this routine can be used to pass a pointer to the custom PHY initialization routine. Parameters: `TEthernet_PHYInit_Ptr:` pointer to the custom PHY initialization routine.
Requires	Nothing.
Example	Ethernet_SetPHYInit(@Phy_Init)

Ethernet_Set_Default_PHY

Prototype	sub procedure Ethernet_Set_Default_PHY()
Returns	Nothing.
Description	initializes the PHY SMSC 8720A chip (present on the mikroElektronika's MultiMedia Board for PIC32MX7) to the library default. Parameters: None.
Requires	Nothing.
Example	Ethernet_Set_Default_PHY()

Ethernet_Enable

Prototype

sub procedure Ethernet_Enable(dim enFlt as word)

Returns

Nothing.

Description

This is MAC module routine. This routine enables appropriate network traffic on the MCU's internal Ethernet 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. _Ethernet_BROADCAST

1 0x02 MAC Multicast traffic/receive filter flag. When set, MAC multicast traffic will be enabled. _Ethernet_MULTICAST

2 0x04 not used none

3 0x08 MAC Unicast traffic/receive filter flag. When set, MAC unicast traffic will be enabled. _Ethernet_UNICAST

4 0x10 not used none

5 0x20 not used none

6 0x40 CRC check flag. When set, packets with invalid CRC field will be discarded. _Ethernet_CRC

7 0x80 not used none

Note :

Advanced filtering available in the MCU's internal Ethernet 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 MCU's internal Ethernet module.
The MCU's internal Ethernet module should be properly cofigured by the means of Ethernet_Init routine.

Requires

Ethernet module has to be initialized. See Ethernet_Init.

Example

Ethernet_Enable(_Ethernet_CRC or _Ethernet_UNICAST) ' enable CRC checking and Unicast traffic

Ethernet_Disable

Prototype

sub procedure Ethernet_Disable(dim disFlt as word)

Returns

Nothing.

Description

This is MAC module routine. This routine disables appropriate network traffic on the MCU's internal Ethernet 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:

Note :

Advance filtering available in the MCU's internal Ethernet 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 MCU's internal Ethernet module.
The MCU's internal Ethernet module should be properly cofigured by the means of Ethernet_Init routine.

Requires

Ethernet module has to be initialized. See Ethernet_Init.

Example

Ethernet_Disable(_Ethernet_CRC or _Ethernet_UNICAST) ' disable CRC checking and Unicast traffic

Ethernet_doPacket

Prototype	sub function Ethernet_doPacket() as byte
Returns	`0` - upon successful packet processing (zero packets received or received packet processed successfully). `1` - upon reception error or receive buffer corruption. Ethernet 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 Ethernet_UserTCP function is called for further processing. upon UDP request the Ethernet_UserUDP function is called for further processing. Note : `Ethernet_doPacket` must be called as often as possible in user's code.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	while true ... Ethernet_doPacket() ' process received packets ... wend

Ethernet_putByte

Prototype	sub procedure Ethernet_putByte(dim v as byte)
Returns	Nothing.
Description	This is MAC module routine. It stores one byte at current write location. Parameters: `v:` value to store
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	dim data as byte ... Ethernet_putByte(data) ' put an byte into buffer

Ethernet_putBytes

Prototype	sub procedure Ethernet_putBytes(dim ptr as ^byte, dim n as word)
Returns	Nothing.
Description	This is MAC module routine. It stores requested number of bytes into RAM at current write location. Parameters: `ptr:` RAM buffer containing bytes to be written into RAM. `n:` number of bytes to be written.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	dim buffer as byte[17] ... buffer = "mikroElektronika" ... Ethernet_putBytes(buffer, 16) ' put an RAM array into buffer

Ethernet_putConstBytes

Prototype	sub procedure Ethernet_putConstBytes(const ptr as ^byte, dim n as word)
Returns	Nothing.
Description	This is MAC module routine. It stores requested number of const bytes into RAM at current write location. Parameters: `ptr:` const buffer containing bytes to be written into RAM. `n:` number of bytes to be written.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	const buffer as byte[17] ... buffer = "mikroElektronika" ... Ethernet_putConstBytes(buffer, 16) ' put a const array into buffer

Ethernet_putString

Prototype	sub function Ethernet_putString(dim ptr as ^byte) as word
Returns	Number of bytes written into RAM.
Description	This is MAC module routine. It stores whole string (excluding null termination) into RAM at current write location. Parameters: `ptr:` string to be written into RAM.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	dim buffer as string[16] ... buffer = "mikroElektronika" ... Ethernet_putString(buffer) ' put a RAM string into buffer

Ethernet_putConstString

Prototype	sub function Ethernet_putConstString(const ptr as ^byte) as word
Returns	Number of bytes written into RAM.
Description	This is MAC module routine. It stores whole const string (excluding null termination) into RAM at current write location. Parameters: `ptr:` const string to be written into RAM.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	const buffer as string[16] ... buffer = "mikroElektronika" ... Ethernet_putConstString(buffer) ' put a const string into buffer

Ethernet_getByte

Prototype	sub function Ethernet_getByte() as byte
Returns	Byte read from RAM.
Description	This is MAC module routine. It fetches a byte from address pointed to by current read location.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	dim buffer as byte ... buffer = Ethernet_getByte() ' read a byte from buffer

Ethernet_getBytes

Prototype	sub procedure Ethernet_getBytes(dim ptr as ^byte, dim addr as word, dim n as word)
Returns	Nothing.
Description	This is MAC module routine. It fetches requested number of bytes from RAM from address pointed to by current read location. If value of `0xFFFF` is passed as the address parameter, the reading will start from current read location. Parameters: `ptr:` buffer for storing bytes read from RAM. `addr:` RAM start address. Valid values: `0`..`8192`. `n:` number of bytes to be read.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	dim buffer as byte[16] ... Ethernet_getBytes(buffer, 0x100, 16) ' read 16 bytes, starting from address 0x100

Ethernet_UserTCP

Prototype	sub function Ethernet_UserTCP(dim byref remoteHost as byte[4], dim remotePort, localPort, reqLength as word, dim byref flags as TEthPktFlags) as word
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 Ethernet_get routines. The user puts data in the transmit buffer by using some of the 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 fields : Copy Code To Clipboard structure TEthPktFlags dim canCloseTCP as boolean ' flag which closes socket dim isBroadcast as boolean ' flag which denotes that the IP package has been received via subnet broadcast address (not used for PIC16 family) end structure 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. See Ethernet_Init.
Example	This function is internally called by the library and should not be called by the user's code.

Ethernet_UserUDP

Prototype	sub function Ethernet_UserUDP(dim byref remoteHost as byte[4], dim remotePort, destPort, reqLength as word, dim byref flags as TEthPktFlags) as word
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 Ethernet_get routines. The user puts data in the transmit buffer by using some of the 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 fields : Copy Code To Clipboard structure TEthPktFlags dim canCloseTCP as boolean ' flag which closes socket (not relevant to UDP) dim isBroadcast as boolean ' flag which denotes that the IP package has been received via subnet broadcast address (not used for PIC16 family) end structure 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. See Ethernet_Init.
Example	This function is internally called by the library and should not be called by the user's code.

Ethernet_getIpAddress

Prototype	sub function Ethernet_getIpAddress() as word
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. See Ethernet_Init.
Example	dim ipAddr as byte[4] ' user IP address buffer ... memcpy(ipAddr, Ethernet_getIpAddress(), 4) ' fetch IP address

Ethernet_getGwIpAddress

Prototype	sub function Ethernet_getGwIpAddress() as word
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. See Ethernet_Init.
Example	dim gwIpAddr as byte[4] ' user gateway IP address buffer ... memcpy(gwIpAddr, Ethernet_getGwIpAddress(), 4) ' fetch gateway IP address

Ethernet_getDnsIpAddress

Prototype	sub function Ethernet_getDnsIpAddress() as word
Returns	Pointer to the global variable holding DNS IP address.
Description	This 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. See Ethernet_Init.
Example	dim dnsIpAddr as byte[4] ' user DNS IP address buffer ... memcpy(dnsIpAddr, Ethernet_getDnsIpAddress(), 4) ' fetch DNS server address

Ethernet_getIpMask

Prototype	sub function Ethernet_getIpMask() as word
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. See Ethernet_Init.
Example	dim IpMask as byte[4] ' user IP subnet mask buffer ... memcpy(IpMask, Ethernet_getIpMask(), 4) ' fetch IP subnet mask

Ethernet_confNetwork

Prototype	sub procedure Ethernet_confNetwork(dim byref ipMask, gwIpAddr, dnsIpAddr as byte[4])
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. Note : The above mentioned network parameters should be set by this routine only if DHCP module is not used. Otherwise DHCP will override these settings.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	dim ipMask as byte[4] ' network mask (for example : 255.255.255.0) gwIpAddr as byte[4] ' gateway (router) IP address dnsIpAddr as byte[4] ' DNS server IP address ... gwIpAddr[0] = 192 gwIpAddr[1] = 168 gwIpAddr[2] = 20 gwIpAddr[3] = 6 dnsIpAddr[0] = 192 dnsIpAddr[1] = 168 dnsIpAddr[2] = 20 dnsIpAddr[3] = 100 ipMask[0] = 255 ipMask[1] = 255 ipMask[2] = 255 ipMask[3] = 0 ... Ethernet_confNetwork(ipMask, gwIpAddr, dnsIpAddr) ' set network configuration parameters

Ethernet_arpResolve

Prototype	sub function Ethernet_arpResolve(dim byref ip as byte[4], dim tmax as byte) as word
Returns	MAC address behind the IP address - the requested IP address was resolved. `0` - otherwise.
Description	This is ARP module routine. It sends an ARP request for given IP address and waits for ARP reply. If the requested IP address was resolved, an ARP cash entry is used for storing the configuration. ARP cash can store up to 3 entries. For ARP cash structure refer to `"__EthernetPrivate.mbas"` file in the compiler's Uses folder. Parameters: `ip:` IP address to be resolved. `tmax:` time in seconds to wait for an reply. Note : The Ethernet services are not stopped while this routine waits for ARP reply. The incoming packets will be processed normaly during this time.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	dim IpAddr as byte[4] ' IP address ... IpAddr[0] = 192 IpAddr[0] = 168 IpAddr[0] = 1 IpAddr[0] = 1 ... Ethernet_arpResolve(IpAddr, 5) ' get MAC address behind the above IP address, wait 5 secs for the response

Ethernet_sendUDP

Prototype	sub function Ethernet_sendUDP(dim byref destIP as byte[4], dim sourcePort, destPort as word, dim pkt as ^byte, dim pktLen as word) as byte
Returns	`1` - UDP packet was sent successfully. `0` - otherwise.
Description	This is UDP module routine. It sends an UDP packet on the network. Parameters: `destIP:` remote host IP address. `sourcePort:` local UDP source port number. `destPort:` destination UDP port number. `pkt:` packet to transmit. `pktLen:` length in bytes of packet to transmit.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	dim IpAddr as byte[4] ' remote IP address ... IpAddr[0] = 192 IpAddr[0] = 168 IpAddr[0] = 1 IpAddr[0] = 1 ... Ethernet_sendUDP(IpAddr, 10001, 10001, "Hello", 5) ' send Hello message to the above IP address, from UDP port 10001 to UDP port 10001

Ethernet_dnsResolve

Prototype	sub function Ethernet_dnsResolve(dim byref host as string, dim tmax as byte) as word
Returns	pointer to the location holding the IP address - the requested host name was resolved. `0` - otherwise.
Description	This is DNS module routine. It sends an DNS request for given host name and waits for DNS reply. If the requested host name was resolved, it's IP address is stored in library global variable and a pointer containing this address is returned by the routine. UDP port `53` is used as DNS port. Parameters: `host:` host name to be resolved. `tmax:` time in seconds to wait for an reply. The above mentioned network parameters should be set by this routine only if DHCP module is not used. Otherwise DHCP will override these settings. Note : The Ethernet services are not stopped while this routine waits for DNS reply. The incoming packets will be processed normaly during this time. User should always copy the IP address from the RAM location returned by this routine into it's own resolved host IP address buffer. These locations should not be altered by the user in any case!
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	dim remoteHostIpAddr as byte[4] ' user host IP address buffer ... ' SNTP server: ' Zurich, Switzerland: Integrated Systems Lab, Swiss Fed. Inst. of Technology ' 129.132.2.21: swisstime.ethz.ch ' Service Area: Switzerland and Europe memcpy(remoteHostIpAddr, Ethernet_dnsResolve("swisstime.ethz.ch", 5), 4)

Ethernet_initDHCP

Prototype	sub function Ethernet_initDHCP(dim tmax as byte) as byte
Returns	`1` - network parameters were obtained successfully. `0` - otherwise.
Description	This is DHCP module routine. It sends an DHCP request for network parameters (IP, gateway, DNS addresses and IP subnet mask) and waits for DHCP reply. If the requested parameters were obtained successfully, their values are stored into the library global variables. These parameters can be fetched by using appropriate library IP get routines: Ethernet_getIpAddress - fetch IP address. Ethernet_getGwIpAddress - fetch gateway IP address. Ethernet_getDnsIpAddress - fetch DNS IP address. Ethernet_getIpMask - fetch IP subnet mask. UDP port `68` is used as DHCP client port and UDP port `67` is used as DHCP server port. Parameters: `tmax:` time in seconds to wait for an reply. Note : The Ethernet services are not stopped while this routine waits for DNS reply. The incoming packets will be processed normaly during this time. When DHCP module is used, global library variable `Ethernet_userTimerSec` is used to keep track of time. It is user responsibility to increment this variable each second in it's code.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	... Ethernet_initDHCP(5) ' get network configuration from DHCP server, wait 5 sec for the response ...

Ethernet_doDHCPLeaseTime

Prototype	sub function Ethernet_doDHCPLeaseTime() as byte
Returns	`0` - lease time has not expired yet. `1` - lease time has expired, it's time to renew it.
Description	This is DHCP module routine. It takes care of IP address lease time by decrementing the global lease time library counter. When this time expires, it's time to contact DHCP server and renew the lease.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	while true ... if(Ethernet_doDHCPLeaseTime() <> 0) then ... ' it's time to renew the IP address lease end if wend

Ethernet_renewDHCP

Prototype	sub function Ethernet_renewDHCP(dim tmax as byte) as byte
Returns	`1` - upon success (lease time was renewed). `0` - otherwise (renewal request timed out).
Description	This is DHCP module routine. It sends IP address lease time renewal request to DHCP server. Parameters: `tmax:` time in seconds to wait for an reply.
Requires	Ethernet module has to be initialized. See Ethernet_Init.
Example	while true ... if(Ethernet_doDHCPLeaseTime() <> 0) then Ethernet_renewDHCP(5) ' it's time to renew the IP address lease, with 5 secs for a reply end if ... wend

Want more examples and libraries?
Find them on