"Sn_TX_RD", "Sn_TX_WR" and "Sn_TX_FSR" reading problem [W5500]

Question

Hello. Before any question excuse me for my English. My language isn’t English. I want to write a simple test code for W5500 with Arduino Due. W5500 works as a client and my PC works as a server. The code saves a character in TX buffer and sends it to my PC. My code performs the following tasks: loading common registers with appropriate values opening the socket0 in TCP mode connecting to server until here all things are perfect, but when i run send command (Sn_CR=0x20), the server receives arbitrary bytes. I perform updating process of Sn_TX_WR with respect to data sheet. Also, according to W5500 data sheet after connecting to server in TCP mode, the value of Sn_TX_RD and Sn_TX_WR will be re-initialized to 0x0000. But when i read these registers after connect command (Sn_CR=0x04), W5500 returns arbitrary numbers for both and these values are same for these registers. Also the value of Sn_TX_FSR reads as 0X0800 which is correct. When i read these registers after send command (Sn_CR=0x20), W5500 returns 0x0000 for Sn_TX_WR and Sn_TX_RD and an arbitrary number for Sn_TX_FRS. I don’t know where is the problem. Can anyone help me??? Thanks in advance.

Mxyxixptlick · Answer

What software is acting as a server on your PC, and how do you know the problem isn’t there?

Dan1 · Answer

Hi, I have same problem now…! When sending string to a server I get a lot of “garbage” with the string. Reading getSn_TX_FSR before sending give 800h (2048) as expected but after sending the value is “strange” and not what I expect (2048 - string lengh)… What was the writing mistake? can you share it? Any Idea? Dan Groswirth cellkey.tech.gmail.com

cellkey · Answer

Hello e_sh: Thanks for your response. The way you suggest to update pointer is not documented as far as I know. I have not seen it in any of the examples I have seen. Dont understand the " (Sn_TX_RD0 & Sn_TX_RD1)" that you mentioned. I use Sn_Tx_WR to get the pointer to writing location, as done at the send() rutine in socket.c file. Please explain your idea . Thanks Dan

Dan1 · Answer

Hello e_sh: Thanks again for your support. I am getting into your code in order to understand the lower level of the handling of the appropriate registers… You read TX_RD to set the writing address while W5500 library show reading TX_WR as in that code: //writing data to TX buffer void wiz_send_data(uint8_t sn, uint8_t *wizdata, uint16_t len) { uint16_t ptr = 0; uint32_t addrsel = 0; if(len == 0) return; ptr = getSn_TX_WR(sn); //<<<<<<setting the pointer addrsel = ((uint32_t)ptr << 8) + (WIZCHIP_TXBUF_BLOCK(sn) << 3); WIZCHIP_WRITE_BUF(addrsel,wizdata, len); ptr += len; setSn_TX_WR(sn,ptr); } I still confused about handling the TX_WR and TX_RD pointers as I have problem that data I send is seen on server wrapped by “endless” garbage bytes and written several times… Regards Dan

e sh · Answer

Hi Dan1. Yes. The code is written for W5500. According to description of Sn_TX_RD in datasheet (page 54): SEND command transmits the saved data from the current Sn_TX_RD to the Sn_TX_WR in the socket n TX buffer. After transmitting the saved data, the SEND command increases the Sn_TX_RD as same as the Sn_TX_WR. Hence, i think in the “wiz_send_data” routine, at line : ptr = getSn_TX_WR(sn); //<<<<<<setting the pointer the Sn_TX_RD and Sn_TX_WR registers have the same value. Are you sure about your code on server side? Thank you.