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spi communication

hello all,
i am interfacing arm7 i.e lpc2148 with 7366 using spi. i want to know how many devices can we interface using spi?
thank you

Parents
  • From an electrical point of view, it's the signal load that decides how many listeners you can have on a signal - the dynamic and static load. So you just have to figure out how much current you have available and how much current that is needed (also taking into account the capacitive load which is the main problem for CMOS devices). With slower SPI speeds, you can accept larger capacitive loads.

    The other issue is that you can't have two slave devices talk at the same time (which would garble the MISO signal), so you will need one slave select signal for each 7366.

Reply
  • From an electrical point of view, it's the signal load that decides how many listeners you can have on a signal - the dynamic and static load. So you just have to figure out how much current you have available and how much current that is needed (also taking into account the capacitive load which is the main problem for CMOS devices). With slower SPI speeds, you can accept larger capacitive loads.

    The other issue is that you can't have two slave devices talk at the same time (which would garble the MISO signal), so you will need one slave select signal for each 7366.

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