Spi

#1

Hi,

I have several questions about SPI interface:

Q1: How many data bits shall I use when talking to WizFi250 via SPI ?
Q2: Can I make burst data transfers with a single SPI_SS assert on or shall I toggle SPI_SS on every data transfer? It would be good to see examples of the waveforms somewhere in the datasheet.
Q3: Here wizwiki.net/wiki/doku.php?id=pro … escription. What pin is used as SPI_DATA_READY output?

Thanks in advance for your help!

#2

Hi

Q1: How many data bits shall I use when talking to WizFi250 via SPI ?
[color=#FF0000]A1: WizFi250 support to send and received 1byte data after SPI_SS is set low.[/color]

Q2: Can I make burst data transfers with a single SPI_SS assert on or shall I toggle SPI_SS on every data transfer? It would be good to see examples of the waveforms somewhere in the datasheet.
[color=#FF0000]A2: Yes, WizFi250 is not supported burst data transfer with a single SPI_SS. So WizFi250 have to toggle SPI_SS on every data transfer. Please refer to this example source code. ( https://github.com/Wiznet/Arduino_WizFi250 )
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Q3: Here wizwiki.net/wiki/doku.php?id=pro … escription. What pin is used as SPI_DATA_READY output?
[color=#FF0000]A3: SPI_DATA_READY pin is GPIO14. we modified wiki page.[/color]

#3

Great! This helps a lot, especially the source code! One other question though: what is maximum SPI clock frequency allowed?

#4

Hi

WizFi250 can use spi clock up to 2.25Mbps. But WizFi250 can’t use full speed of spi clock due to the fact that WizFi250 is not supported burst data transfer with a single SPI_SS.