W6100 read/write MAC

TCP/IP Chip W6100
1

Hello!

When on startup I try to write MAC address I use the following SPI command:

41 20 04 01 02 03 04 05 06

And I get response:
01 02 03 00 00 00 00 00 00

But then I try to read it with:
41 20 00 00 00 00 00 00 00
And get the reply:
01 02 03 00 00 00 00 00 00

My SPI comms work as I get 01 02 03 at the start. But why the register is empty?

2

Hello

There’s no address inside the chip.
You have to buy it separately and add address.

Thank you

3

Hello louis,
I am facing same type of problem in my project where I am using valid MAC value “0x0013E1170001”.
Steps are:
41 20 04 00 13 E1 17 00 01

And I get response:
01 02 03 00 00 00 00 00 00

But then I try to read it with:
41 20 00 00 00 00 00 00 00
And get the reply:
01 02 03 00 00 00 00 00 00

Please let me know what can be the issue?

Thanks,
Himmat

4

Hi,

your SPI stream is correct. You address 0x4120 (first byte of SHAR), Bank 0 (common registers) and you try writing variable length (0x04) and then reading variable length (0x00).

I had issues with my breadbord wirings, where i thought, it was software (read my thread about this). Try reading the CIDR and VER registers to verify your SPI is working properly.

What is your SPI speed?