STM32 - WIZnet W5500

The WIZnet W5500 Ethernet chip provides an easy Ethernet network solution for many microprocessors/microcontrollers. Using a SPI interface and sample library code, most any processor can use this device to get connected to a network.

Hardware Interface

In my case, I purchased a small development module from Amazon.com.
This same module is readily available on Ebay.com and Aliexpress.com
Examples:
  https://www.amazon.com/AITRIP-Ethernet-Hardware-Microcontroller-Interface/dp/B09FG5VZFS/ref=sr_1_10   
  https://www.aliexpress.us/item/3256801465688850.html

A 10 conductor, 2x5 pin header, provides the electrical connection between the host and this module
I wired mine using a female-female ribbon cable as follows:
Wire Color   Signal	 W5500 Module Pin  NUCLEO-F103RB Pin	Comment
Brown        Not Connected  J1-1             NC		
Red          SPI-SCLK       J1-2             SCLK	SPI2_SCK, PB13, CN10-30	
Orange       INTn           J1-3             INT	PB11, CN10-18	Active low
Yellow       SPI-CSn        J1-4             SCS	SPI2_NCS, PB12, CN10-16	Active Low Chip Select
Green        RSTn           J1-5             nRST	PB10, CN10-25	Active Low, 500us min
Blue         MOSI           J1-6             MOSI	SPI2_MOSI, PB15, CN10-26	
Violet       GND            J1-7             GND	GND, CN10-20	
Grey         MISO           J1-8             MISO	SPI2_MISO, PB14, CN10-28	
White        5.0V (NC)      J1-9             NC		
Black        3.3V           J1-10            3.3V	+3V3, CN7-16

Information in the comment field describes what pin/function I connected to on my NUCLEO-F103RB board.

Target Software Interface

The WIZnet software library, "ioLibrary_Driver-master", https://github.com/Wiznet/ioLibrary_Driver
interfaces to the target via function pointers.
Need to implement the following functions (function name not important):
void W5500_Select(void);   // Drive the SPI-CSn signal low, selecting the device
void W5500_Deselect(void); // Drive the SPI-CSn signal high, deselecting the device
void W5500_WriteByte(void); // Write a single byte to the device
uint8_t W5500_ReadByte(void); // Read a single byte from the device
void W5500_WriteBuff(uint8_t* buff, uint16_t len); // Write one or more bytes from a buffer
void W5500_ReadBuff(uint8_t* buff, uint16_t len);  // Read one or more bytes into a buffer

For DHCP, a couple call-back functions need implementations:
void Callback_IP_Assigned(void);
void Callback_IP_Conflict(void);

SPI Interface

The SPI interface, host side, is configured to use SPI2 (SPI1 has LED2 in conflict with SPI1_SCK).
Mode: Full-Duplex Master
Hardware NSS Signal: Diable  (We will manage the active low chip select, NCS signal, with software)
Frame Format: Motorola
Data Size: 8-bits
First Bit: MSB First
Prescaler: 32 - This creates a 1.125MBits/sec SCK
Clock Polarity (CPOL): Low
Clock Phase (CPHA) 1 Edge (First Edge)
CRC Calculation: Disabled
NSS Signal Type: Software

Hardware Reset

Although some example code doesn't use the hardware reset, I manage a hardware reset using PB10.


Examining the first frame of data transfer with the device


View showing blocks of data being transferred in different periods of time following reset.


Wireshark display of DHCP capture (managed network switch with port mirroring required):

Calling w5500_init() from command_line

>init
w5500_init()
w5500_hardware_reset()
Registering W5500 callbacks...
Calling wizchip_init()...
wizchip_sw_reset()
wizchip_init() Success!
PHY Link Up
PHY Link Time: 1531ms
Calling DHCP_init()...
w5500_init(), MAC:EA 11 22 33 44 EA
Registering DHCP callbacks...
Calling DHCP_run()...
IP assigned! Leased time: 86400 sec
DHCP Time: 3884ms
IP:  192.168.1.126
GW:  192.168.1.1
Net: 255.255.255.0
DNS: 192.168.1.1
Calling wizchip_setnetinfo()...
Calling DNS_init()...