WIZnet Developer Forum

W5200 (WIZ820io) module - No Data on MISO line

I had a working circuit with Wiznet W5100, but to get better performance I switched over to Wiznet W5200 (in Wiz820io module). This involved rewiring the pins, changing the register address and also the Read/Write code for the ethernet module as this chip supports Burst Write.

However (this has me totally stumped), when I power on the circuit and read the registers that I have just written to (GATEWAY, IP etc), all I get is 0x00.

This is what I got using logic analyzer. The MISO line is completely flat.


These are my read/write routines for the Ethernet module :

[code] //OP CODES (TO BE OR’ED WITH UPPER 7 BITS OF ADDRESS)
#define W5200_WRITE 0x80
#define W5200_READ 0x00

//BURST WRITING FOR W5200. FOR DATA LENGTH = 1, DEFAULTS TO BYTE WRITE
void ETHERNET_WRITE(uint16_t address, uint8_t *data, uint16_t len)
{
	W5200_SS_LOW;		//SET W5200 SS LOW

	SPI_TXRX((address & 0xFF00)>>8); //WRITE HIGH BYTE OF 2 BYTE ADDRESS
	while(SPI_DATA_RECEIVED==0);

	SPI_TXRX((address & 0x00FF)); //WRITE LOW BYTE OF 2 BYTE ADDRESS		
	while(SPI_DATA_RECEIVED==0);
	
	SPI_TXRX(W5200_WRITE | ((len & 0x7F00)>>8));	//WRITE OPCODE | DATA LENGTH (UPPER 7 BITS)
	while(SPI_DATA_RECEIVED==0);

	SPI_TXRX(len & 0x00FF); //DATA LENGTH (LOWER 8 BITS)
	while(SPI_DATA_RECEIVED==0);

	for(uint16_t i=0; i<len; i++)
	{
		SPI_TXRX(data[i]); //WRITE DATA
		while(SPI_DATA_RECEIVED==0);
	}

	W5200_SS_HIGH; //TURN BACK SS HIGH
}

//BURST READING FOR W5200. FOR DATA LENGTH = 1, DEFAULTS TO BYTE READ
void ETHERNET_READ(uint16_t address, uint8_t len, uint8_t* retval)
{
	W5200_SS_LOW;		//SET W5200 SS LOW
	
	SPI_TXRX((address & 0xFF00)>>8); //WRITE HIGH BYTE OF 2 BYTE ADDRESS
	while(SPI_DATA_RECEIVED==0);
	
	SPI_TXRX(address & 0x00FF); //WRITE LOW BYTE OF 2 BYTE ADDRESS		
	while(SPI_DATA_RECEIVED==0);

	SPI_TXRX(W5200_READ | ((len & 0x7F00)>>8)); //READ OPCODE | DATA LENGTH (UPPER 7 BITS)
	while(SPI_DATA_RECEIVED==0);

	SPI_TXRX(len & 0x00FF); //DATA LENGTH (LOWER 8 BITS)
	while(SPI_DATA_RECEIVED==0);

	for(uint8_t i=0; i<len; i++)
	{
		SPI_TXRX(0x00); //WRITE DUMMY DATA TO READ DATA
		while(SPI_DATA_RECEIVED==0);
		retval[i] = SPI_RX_DATA;
	}
	W5200_SS_HIGH;	//SET SS HIGH
}[/code]

And this is my init routine (on AVR)

[code]void ETHERNET_INIT(uint16_t ip_address, uint16_t subnet_address, uint16_t gateway_address, uint16_t mac)
{
uint8_t val[6];
uint8_t retval[6];
uint8_t i;

	W5200_RESET_LOW;
	_delay_us(50);
	W5200_RESET_HIGH;
	for(i=0;i<20; i++)
	{
		_delay_ms(20);
	}

	val[0] = MR_RST;
	ETHERNET_WRITE(MR, val,1);
	ETHERNET_READ(MR, 1, retval);
	while(retval[0] !=0) {ETHERNET_READ(MR, 1, retval);}

	printf("*** Ethernet ****\r");

	//if(ETHERNET_DEBUG)
	//{
		ETHERNET_READ(MR, 1, retval);
		printf("Reading MR : %u\r", retval[0]); 
	//}

	//set IP Address
	EEPROM_READ(ip_address, 4, retval);
	ETHERNET_WRITE(SIPR, retval, 4);
	//if(ETHERNET_DEBUG)
	//{
		ETHERNET_READ(SIPR, 4, retval);
		printf("IP Address : %u.%u.%u.%u\r",retval[0],retval[1],retval[2],retval[3]);
		
	//}

	//set subnet mask
	EEPROM_READ(subnet_address, 4, retval);
	ETHERNET_WRITE(SUBR, retval, 4);
	//if(ETHERNET_DEBUG)
	//{
		ETHERNET_READ(SUBR, 4, retval);
		printf("Subnet Mask : %u.%u.%u.%u\r",retval[0],retval[1],retval[2],retval[3]);
	//}

	//set gateway address
	EEPROM_READ(gateway_address, 4, retval);
	ETHERNET_WRITE(GWR, retval, 4);
	//if(ETHERNET_DEBUG)
	//{
		ETHERNET_READ(GWR, 4, retval);
		printf("Gateway ip Address : %u.%u.%u.%u\r",retval[0],retval[1],retval[2],retval[3]);
	//}

	//set mac address
	EEPROM_READ(mac, 6, retval);
	ETHERNET_WRITE(SHAR, retval, 6);
	//if(ETHERNET_DEBUG)
	//{
		ETHERNET_READ(SHAR, 6, retval);
		printf("mac Address : %02X.%02X.%02X.%02X.%02X.%02X\r",retval[0],retval[1],retval[2],retval[3],retval[4],retval[5]);
	//}

	//set interrupt high time
	val[0] = 1;
	ETHERNET_WRITE(INTLEVEL, val, 1);

	//set TX and RX memory to 2KB per socket
	//val[0] = 0x55;
	//ETHERNET_WRITE(RMSR, val, 1);
	//ETHERNET_WRITE(TMSR, val, 1);

	//set TX = 8Kb RX = 8Kb for Sock 0 & Sock 1
	val[0] = 0x08;
	ETHERNET_WRITE(SOCKET_0_REGISTER_BASE + SN_RX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_0_REGISTER_BASE + SN_TX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_1_REGISTER_BASE + SN_RX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_1_REGISTER_BASE + SN_TX_MEMSIZE, val, 1);
	val[0] = 0x00;
	ETHERNET_WRITE(SOCKET_2_REGISTER_BASE + SN_RX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_2_REGISTER_BASE + SN_TX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_3_REGISTER_BASE + SN_RX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_3_REGISTER_BASE + SN_TX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_4_REGISTER_BASE + SN_RX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_4_REGISTER_BASE + SN_TX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_5_REGISTER_BASE + SN_RX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_5_REGISTER_BASE + SN_TX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_6_REGISTER_BASE + SN_RX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_6_REGISTER_BASE + SN_TX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_7_REGISTER_BASE + SN_RX_MEMSIZE, val, 1);
	ETHERNET_WRITE(SOCKET_7_REGISTER_BASE + SN_TX_MEMSIZE, val, 1);


	//set RTR - retry time value register for timeout @ 2000us
	val[0] = 0x07;
	val[1] = 0xD0;
	ETHERNET_WRITE(RTR, val, 2);
	//if(ETHERNET_DEBUG)
	//{
		ETHERNET_READ(RTR, 2, retval);
		printf("rtr : %x:%x\r", retval[0], retval[1]);
	//}

	//set RCR - max retry count to 8
	val[0] = 0x08;
	ETHERNET_WRITE(RCR, val, 1);
	//if(ETHERNET_DEBUG)
	//{
		ETHERNET_READ(RCR, 1, retval);
		printf("rcr : %u\r", retval[0]);
	//}

	//enable mask for socket 1 interrupt
	val[0] = IMR_S1_INT;
	ETHERNET_WRITE(IMR, val, 1);
	if(ETHERNET_DEBUG)
	{
		ETHERNET_READ(IMR, 1, retval);
		printf("IMR : 0x%x\r",retval[0]);
	}
}

[/code]

Any ideas why the MISO is always 0 ?

Hi ankitmcgill

MISO value is no data when read the register via SPI, is it right?

I’ve found an error in the post:

0x80 is write operation and data length '0’
Therefore, MISO is no operation and ‘0’ value is correct.

If you want to read the register, you should be setting the opcode value as ‘0’.

thanks
EK :slight_smile:

[quote=“ekkim”]Hi ankitmcgill

MISO value is no data when read the register via SPI, is it right?

I’ve found an error in the post:

0x80 is write operation and data length '0’
Therefore, MISO is no operation and ‘0’ value is correct.

If you want to read the register, you should be setting the opcode value as ‘0’.

thanks
EK :slight_smile:[/quote]

Hi EK,

In the logic analyzer output that I’ve posted above the data I am sending on to MOSI line is,

byte 1 : 0x00 (address upper byte)
byte 2 : 0x19 (address lower byte)
byte 3 : 0x80 (write opcode | Length upper 7 bits)
byte 4 : 0x01 (length lower 8 bits)
byte 5 : 0x08 (data to be written)

This should write 0x08 to location 0x19 (RCR)

In the second SPI transfer I am sending the following on MOSI

byte 1 : 0x00 (address upper byte)
byte 2 : 0x19 (address lower byte)
byte 3 : 0x00 (read opcode | Length upper 7 bits)
byte 4 : 0x01 (length lower 8 bits)
byte 5 : 0x00 (dummy data)

This should read 1 byte off the address 0x19 (RCR) and hence I should get 0x08 on the MISO line. Isn’t that correct way of doing?

Thanks
Ankit :slight_smile:

Hi~

You are right.
but in case of RCR, this register have initial value as ‘0x08’.
RCR write the value after it read the value.

Please refer to the attached picture.(for example, 0x0001(GAR0))
This picture measure the SPI communication using oscilloscope about Read/Write operaion.

thanks
EK :slight_smile:



Dear Ekk, I am not sure if I understood what you wrote . Can you please clarify.

Also i tried with another wiz820io module and this time when I power on, I get both the orange and green lights on the RJ45 jack blinking. They just keep on blinking. The module is not able to get a link.

Thanks ! :slight_smile:
ankit

Hi~

First checking point,
Please confirm the attached file.


- After power on, nRESET status high -> low ->high
- Please confirm the nSS(low) during MOSI transmission.
- PWDN set up the ‘low’
- we does support SPI Mode0 and SPI Mode3.
second,
Please let me know the operation frequency?

The last,
wiz820io is no blinking and no SPI communication when power on. Is it correct?
If wiz820io module is a faulty product, we will provide RMA until warranty.

Thanks,
EK :slight_smile:

Dear Ek,

Thank you for the support.

I did find the issue. The i/o pin from which I was controlling the nReset line to the Wiz820io module was faulty and was never going down to 0V. Hence the module was never getting resetted.

Using a different pin for nReset on my MCU solved the issue.

The module is working perfectly now :slight_smile:

Hi~

I’m also pleased that the problem have been resolved.
I’ll be right here it you need me.

Thanks
EK :slight_smile:

Hello everyone,

I’ve exactly the same problem, but I don’t get how to fix it yet?
What does the reset pin has to do with the W5200? do I’ve to do a reset while reading?

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