General • Re: New to SPI

You have two options: two SPI masters (peripheral devices) - each connects just to one slave or one SPI master and two slaves connected.

Two SPI masters:

• each SPI master provides SCLK, MISO and MOSI (and nCS signal)
• each SCLK can have a different speed, even a different SPI mode
• because just one slave connected to one master: even nCS might not be needed (slave could be connected all the time
• both SPIs are separate, you need more wires (from two SPI masters, all separated, to one slave on each)

One SPI master and two slaves:

• here, the SPI master provides (the same) SCLK, MISO and MOSI to both slaves (in parallel)
• you need TWO nCS signals, exclusive, one or the other slave selected
• the SCLK speed (and mode) is the same for both devices - check if possible for your slave devices
• you need less GPIOs and just one SPI master code (driver)
• but if your slave devices are different in terms of SCLK speed and SPI mode - you have to reconfigure all the time when
  accessing one or the other SPI slave

Statistics: Posted by tjaekel — Sun Sep 01, 2024 8:12 pm

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