
75
32117DS–AVR-01/12
AT32UC3C
Maximum SPI Frequency, Slave Input Mode
The maximum SPI slave input frequency is given by the following formula:
Where
is the MOSI setup and hold time, USPI7 + USPI8 or USPI10 + USPI11 depending
on CPOL and NCPHA.
is the maximum frequency of the CLK_SPI. Refer to the SPI
chapter for a description of this clock.
Maximum SPI Frequency, Slave Output Mode
The maximum SPI slave output frequency is given by the following formula:
Where
is the MISO delay, USPI6 or USPI9 depending on CPOL and NCPHA.
is
the SPI master setup time. Please refer to the SPI masterdatasheet for
.
is the
maximum frequency of the CLK_SPI. Refer to the SPI chapter for a description of this
clock.
is the maximum frequency of the SPI pins. Please refer to the I/O Pin Characteris-
tics section for the maximum frequency of the pins.
7.9.4
SPI Timing
7.9.4.1
Master mode
Figure 7-11. SPI Master Mode With (CPOL= NCPHA= 0) or (CPOL= NCPHA= 1)
fSPCKMAX
MIN
fCLKSPI 2
×
9
-----------------------------
1
SPIn
------------
(,
)
=
SPIn
fCLKSPI
fSPCKMAX
MIN
fCLKSPI 2
×
9
-----------------------------
fPINMAX
,
1
SPIn tSETUP
+
------------------------------------
(,
)
=
SPIn
TSETUP
TSETUP fCLKSPI
fPINMAX
SPI0
SPI1
MISO
SPCK
MOSI
SPI2