Editing Serial Peripheral Interface (section)

===Disadvantages===
* Requires more pins on IC packages than [[I²C]], even in [[Serial Peripheral Interface#Three-wire|three-wire]] variants
* Only handles short distances compared to [[RS-232]], [[RS-485]], or [[CAN-bus]] (though distance can be extended with the use of transceivers like [[RS-422]])
* Extensibility severely reduced when multiple slaves using different SPI Modes are required
** Access is slowed down when master frequently needs to reinitialize in different modes
* No formal standard
** So validating conformance is not possible
** Many existing variations complicate support
* No built-in protocol support for some conveniences:
** No hardware [[flow control (data)|flow control]] by the slave (but the master can delay the next clock edge to slow the transfer rate)
** No hardware slave acknowledgment (the master could be transmitting to nowhere and not know it)
** No error-checking protocol
** No [[hot swapping]] (dynamically adding nodes)
** Interrupts are outside the scope of SPI (see {{Slink|2=Interrupts|nopage=y}})