Digi NS9215 manual I c l o c k i n g m o d e s, Timing modes Clocking mode diagrams

S E R I A L C O N T RO L M O D U L E : S P I

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SPI clocking modes. .

S P I c l o c k i n g m o d e s

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There are four SPI clocking modes. Each mode’s characteristics are defined by the idle value of the clock, which clock edge captures data, and which clock edge drives data. The MODE field in the SPI Configuration register specifies the timing mode.

Timing modes

Clocking mode diagrams

SPI mode	SPI CLK Idle	SPI DATA IN	SPI DATA OUT
		capture edge	drive edge
0	Low	Rising	Falling
1	High	Falling	Rising
2	Low	Falling	Rising
3	High	Rising	Falling

The next two diagrams show the four SPI clocking modes. SPI Mode0 and SPI Mode3 are the most commonly used modes.

SPI Mode0 and Mode3 functional timing

CS#

Mode3	Mode3
CLK
Mode0	Mode0
Capture Edge	Launch Edge
SIN / SOUT
SPI Mode1 and Mode2 functional timing
CS#
Mode1	Mode1
CLK
Mode2	Mode2
Launch Edge	Capture Edge

SIN / SOUT

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