Read/write to Sn_TX_WR register W5500

TCP/IP Chip W5500
1

I can’t read the correct value of this register after writing to it.

example:

   setSn_TX_WR(1, 0x0015);    //write value to this register
ui16tmp = getSn_TX_WR(1);   // i have 0x0000 as result, not  0x0015

I can see with my logic analyser that te correct value (spi) is send

send spi → 00 24 2C 00
→ 00 25 2C 16

read ->00 24 28 FF → result read 00
->00 25 28 FF → result read 00

i can read other registers, but this register give Always zero

2

Sn_TX_WR regsiter are updated by writing SEND of Sn_CR to ‘1’.
The related pointer regsiters are normaly read/write regiter.

Refer to datasheets.

Thank you.