I want to use SPI module in loop-back mode. so I wire MOSI to MISO.

but how about the clock??. is it wired somewhere?? and how the clock works loop-back mode


1 Answer 1


Usually you don't have to wire the clock as the sending device, which transmits also the clock, always samples the data at the same clock it sends the data out.

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    \$\begingroup\$ the chip select is also not needed??? no need to set it low?? \$\endgroup\$
    – makouda
    May 11, 2015 at 8:01
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    \$\begingroup\$ The chip select is needed. Otherwise the chips ignore's the input, even it is sent my himself. In a loop-back configuration you usally only have the chip itself, so you can set the CS to always on. If it has to be low or high depends on the CS if it is low active or high active. \$\endgroup\$ May 11, 2015 at 9:14

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