38.5.5 SPI - Timing Characteristics

Figure 38-5. SPI - Timing Requirements in Host Mode

Table 38-20. SPI - Timing Specifications in Host Mode
Symbol	Description	Min.	Typ.✝	Max.	Unit
f_SCK *	SCK clock frequency	—	—	f_{CLK_PER}/2	MHz
T_SCK *	SCK period	2 × T_{CLK_PER}	—	—	ns
t_SCKW	SCK high/low width	—	0.5 × T_SCK	—	ns
t_MIS	MISO setup to SCK	—	T_{CLK_PER}	—	ns
t_MIH	MISO hold after SCK	—	0	—	ns
t_MOS	MOSI setup to SCK	—	0.5 × T_SCK	—	ns
t_MOH	MOSI hold after SCK	—	0.5 × T_SCK	—	ns
✝ Unless otherwise specified, data in the “Typ.” column is at T_A = 25°C and V_DD = 3.0V. These parameters are not tested and are for design guidance only. * These parameters are characterized but not tested in production.

Figure 38-6. SPI - Timing Requirements in Client Mode

Table 38-21. SPI - Timing Specifications in Client Mode
Symbol	Description	Min.	Typ.✝	Max.	Unit	Condition
f_SSCK *	Client SCK clock frequency	—	—	f_{CLK_PER}/6	MHz
T_SSCK *	Client SCK period	6 × T_{CLK_PER}	—	—	ns
t_SSCKW *	SCK high/low width	3 × T_{CLK_PER}	—	—	ns
t_SIS *	MOSI setup to SCK	0	—	—	ns
t_SIH *	MOSI hold after SCK	3 × T_{CLK_PER}	—	—	ns
t_SSS *	SS setup to SCK	T_{CLK_PER}	—	—	ns
t_SSH *	SS hold after SCK	T_{CLK_PER}	—	—	ns
t_SDLY	Interbyte delay	5 - f_{CLK_PER}/(2 × f_SCK)	—	—	ns	f_SSCK < f_{CLK_PER}/10
t_SDLY	Interbyte delay	0	—	—	ns	f_SSCK ≥ f_{CLK_PER}/10
t_SOS	MISO valid after SCK	—	t_SR	—	ns
t_SOS	MISO valid after SCK	—	—	—	ns
t_SOSS	MISO setup after SS low	—	t_SR	—	ns
t_SOSH	MISO hold after SS low	—	t_SR	—	ns
✝ Unless otherwise specified, data in the “Typ.” column is at T_A = 25°C and V_DD = 3.0V. These parameters are not tested and are for design guidance only. * These parameters are characterized but not tested in production.

AVR64DD14/20