Standard Multi-Slave Communication; Figure 308. Master And Three Independent Slaves - ST STM32F446 Series Reference Manual

Serial peripheral interface/ inter-IC sound (SPI/I2S)
26.3.3

Standard multi-slave communication

In a configuration with two or more independent slaves, the master uses GPIO pins to
manage the chip select lines for each slave (see
of the slaves individually by pulling low the GPIO connected to the slave NSS input. When
this is done, a standard master and dedicated slave communication is established.
1. NSS pin is not used on master side at this configuration. It has to be managed internally (SSM=1, SSI=1) to
prevent any MODF error.
2. As MISO pins of the slaves are connected together, all slaves must have the GPIO configuration of their
MISO pin set as alternate function open-drain (see
page 202).
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Figure 308. Master and three independent slaves

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Figure 308.). The master must select one
Section 7.3.7: I/O alternate function input/output on
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