---
title: "W5100 Listen issue"
url: "https://maker.wiznet.io/forum/9874"
markdown_url: "https://maker.wiznet.io/forum/9874/md"
type: "Forum topic"
category: "Ethernet Chips"
author: "Omer"
created: "2014-01-28T13:54:29+09:00"
last_activity: "2021-04-30T04:48:39+09:00"
language: "en"
views: 1214
replies: 9
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# W5100 Listen issue

## Question

Asked by Omer on 2014-01-28 in Ethernet Chips.

Hi,
I am trying to setup my W5100 module in server mode. I have done the necessary settings, like configuring the GAR, SHAR etc).
I am able to ping the W5100 and after the OPEN command the socket status register’s value is 0x13.
But I am not able to set the listen command.
After executing the listen command the socket status register does not give 0x14.
The status of my Link Leds are
Green Led = Constant ON with no blinking.
Orange Led = blinking

Please let me know what cound be the issue.

Thanks!!!

## Replies

### Reply 1 by hjjeon0608, 2014-01-29

Hi, Omer.

I want to know your code.

Please, post code.

How to set mode register, command and etc.

And I recommend to use reference code at WIZnet.

Best regards.

### Reply 2 by Omer, 2014-01-29

Hi,
I have attached the code files.
Please review them and let me know what I am missing.
I have done the following configurations:

1. RTR = 6000

2. RCR = 3

3. GAR = 192.168.0.2

4. SUBR = 255.255.255.0

5. SHAR = 00:16:36:DE:58:F6 (This is just an dummy mac I am using)

6. SIPR = 192.168.0.48

7. SysInt(0x55, 0x55). This sets 2kB for each socket of Tx and Rx.

8. IMR = 0x01

9. S0_MR = 0x01

10. S0_PORT0 = 502

Thanks!!!
[wiznet_tcp.c](https://maker.wiznet.io/uploads/short-url/rCwsUUFoIp7jsytxUOQLpo8zjlh) (10.8 KB)
[wiznet.h](https://maker.wiznet.io/uploads/short-url/69HXWKTEl2swN4HduylBnhTzwbb) (11.3 KB)
[wiznet.c](https://maker.wiznet.io/uploads/short-url/jBjzTOeSRc99G1uFTOOz0QkFaEO) (43.2 KB)

### Reply 3 by hjjeon0608, 2014-02-03

Hi, Omer.

I think your code is correct.

So, I want to know your main functions.

And I found strange code.

`uint8_t listen(SOCKET s) { uint8_t ucharStatus; ucharStatus = getSn_SR(0); if (ucharStatus == SOCK_INIT) { write_wiznet_reg(Sn_CR(s),Sn_CR_LISTEN); /* wait to process the command... */ while( read_wiznet_reg(Sn_CR(s)) ); /* ------- */ ucharStatus = getSn_SR(0); if(ucharStatus == SOCK_LISTEN) { ucharStatus = 0; } else { close(s); ucharStatus = 1; } } else { close(s); ucharStatus = 1; } return ucharStatus; }`

You use socket number together ‘0’ and ‘s’.
So, please check whether it causes problem.

Best regards.

### Reply 4 by Omer, 2014-02-03

Hi,
I am calling the below function from main:

uint32_t initWiznet(void)
{
//unsigned char MAC_ADDR[6];
uint8_t status = 0x01;

/* Power the wiznet chip */
GPIO_PinOutSet (gpioPortC, 1);
Delay_ms(1);
/* Reset the wiznet chip */
ASSERT_WIZNET_RESET();
Delay_ms(1);
init_usart0_for_wiznet();
DEASSERT_WIZNET_RESET();

setRTR(6000); /* Retry time = 600 ms*/
Delay_ms(1);
setRCR(3); /* Retry count = 3 */
Delay_ms(1);
//setIMR(0x00); /* Interrupt mask */

setGAR(); /* Gateway IP address */
Delay_ms(1);
setSUBR(); /* Subnet mask */
Delay_ms(1);
setSHAR(); /* MAC address */
Delay_ms(1);
setSIPR(); /* Source IP address */
Delay_ms(1);

SysInit(0x55, 0x55); /* TX = 8kB, RX = 8 kB */
Delay_ms(1);
setIMR(IR_SOCK(0)); /* Enable the socket 0 interrupt */
Delay_ms(1);

/* Configure the EFM32 for external interrupt from Wiznet chip */
NVIC_ClearPendingIRQ(GPIO_ODD_IRQn);
NVIC_EnableIRQ(GPIO_ODD_IRQn);

/* Configure PE13 as input */
GPIO_PinModeSet(gpioPortE, 13, gpioModeInput, 1);
/* Set falling edge interrupt */
GPIO_IntConfig(gpioPortE, 13, false, true, true);

write_wiznet_reg(Sn_IR(0), 0xff);

/* Open the socket for server mode */
temp = 1;
/* The below code is for testing purpose only

- It checks if :listen command is properly set.

- Else it loops forever.
  */
  while( temp)
  {
  socket(0, Sn_MR_TCP, 80, 0x00);
  temp = getSn_SR(0);
  temp = listen(0);
  }
  /* Refer to GPIO_ODD_IRQHandler() for further packet processing

- Once connection has been establised, TCP packet processing

- will be carried out based on external interrupt on PE13
  */
  return status;

}

I am trying to connect to socket 0.

### Reply 5 by Omer, 2014-02-04

Hi,
If my code looks Ok, then how can I debug this issues?
Do I need to check something on my desktop side?
If yes then how?
Are there any tools which can help in debugging this issues?

### Reply 6 by hjjeon0608, 2014-02-05

Hi, Omer. I wonder one point. If your MCU is so fast, listen command could be done before SOCK_INIT status changed. SOCK_CLOSED ------changing -------> SOCK_INIT | (listen command here) So, I recommend to use case(1) or debug with changing return value(2). switch(getSn_SR(s)) // check SOCKET status { // ------------ case SOCK_ESTABLISHED: // ESTABLISHED? if(getSn_IR(s) & Sn_IR_CON) // check Sn_IR_CON bit { printf("%d : Connect OK\r\n",s); setSn_IR(s,Sn_IR_CON); // clear Sn_IR_CON } if((len=getSn_RX_RSR(s)) > 0) // check the size of received data { len = recv(s,buf,len); // recv if(len !=send(s,buf,len)) // send { printf("%d : Send Fail.len=%d\r\n",s,len); } } break; // --------------- case SOCK_CLOSE_WAIT: // PASSIVE CLOSED disconnect(s); // disconnect break; // -------------- case SOCK_CLOSED: // CLOSED close(s); // close the SOCKET socket(s,Sn_MR_TCP,port,mode); // open the SOCKET break; // ------------------------------ case SOCK_INIT: // The SOCKET opened with TCP mode listen(s); // listen to any connection request from "TCP CLIENT" printf("%d : LOOPBACK_TCPS(%d) Started.\r\n",s,port); break; default: break; } i.e. check status is SOCK_INIT then command listen. In your while, return value is always 1 if listen is failed. So change return value and then debug what is problem, status is not SOCK_INIT or status is SOCK_INIT but listen command is failed. Try and then reply again please. Best regards.

### Reply 7 by Omer, 2014-02-05

Hi,
Thanks for your replies.
The issues did seem to be with the delay.
I added delay in the wiznet read function and made it same like the wiznet write function.
The issue is resolved now.
Thanks once again for your help!

### Reply 8 by Leytronix, 2021-04-06

Hi Omer,

At the moment I am running into exactly the same issue with the W5100. I understand you solved it with a delay in the read function? I do not understand where that is since the W5100 first has to go into LISTEN mode before anything can be read…

Can you explain that?

Thanks,

Tjerk

### Reply 9 by irina, 2021-04-30 (in reply to reply 8)

In the example above, a delay of 10ms was added after the chip reset.

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Source: https://maker.wiznet.io/forum/9874