Spi full duplex problem

Question

Hello, Im working with stm8s003 and W5500. Im having problems with incoming data from W5500. Pinout Stm8 w5500 Miso---------miso Mosi---------mosi Clk------------clk Cs-------------cs Spi config Fullduplex Msbfirst 8mhz Cpol=1 Cpha=1 With logic analizer i can see that mosi and miso are working, but i always sample 0xFF(if miso is pullup) and 0x00(if miso is pulldown) inside stm8 data register. I have tried miso as floating also. I have tried polling and interrupt spi. I dont know if im doing something wrong. Can W5500 works at 8mhz ? Must it works in full duplex mode? Anyone has any tip? Thanks in advance

Eugeny · Answer

juan_rodri: Can W5500 works at 8mhz ? Datasheet says 33.3 MHz. juan_rodri: Must it works in full duplex mode? Refer to the chapter 2.3 of the datasheet, it comprehensively shows what is going on the SPI bus. When master sends first 3 bytes for the command, W5500 responds with bytes 1, 2, and 3 - therefore it is full duplex, but “data” transferred during this phase is always the same and used for diagnostic purposes to identify if W5500 confirms reception of the command bytes. juan_rodri: i always sample 0xFF(if miso is pullup) and 0x00(if miso is pulldown) inside stm8 data register Suggests you sample at the wrong time.