
73
32117DS–AVR-01/12
AT32UC3C
Maximum SPI Frequency, Master Output
The maximum SPI master output frequency is given by the following formula:
Where
is the MOSI delay, USPI2 or USPI5 depending on CPOL and NCPHA.
is
the maximum frequency of the SPI pins. Please refer to the I/O Pin Characteristics section for
the maximum frequency of the pins.
is the maximum frequency of the CLK_SPI. Refer
to the SPI chapter for a description of this clock.
Maximum SPI Frequency, Master Input
The maximum SPI master input frequency is given by the following formula:
Where
is the MISO setup and hold time, USPI0 + USPI1 or USPI3 + USPI4 depending
on CPOL and NCPHA.
is the SPI slave response time. Please refer to the SPI slave
datasheet for
.
is the maximum frequency of the CLK_SPI. Refer to the SPI
chapter for a description of this clock.
7.9.3.2
Slave mode
Figure 7-8.
USART in SPI Slave Mode With (CPOL= 0 and CPHA= 1) or (CPOL= 1 and
CPHA= 0)
fSPCKMAX
MIN fPINMAX
1
SPIn
------------
fCLKSPI 2
×
9
-----------------------------
,
(,
)
=
SPIn
fPINMAX
fCLKSPI
fSPCKMAX
MIN
1
SPIn tVALID
+
------------------------------------
fCLKSPI 2
×
9
-----------------------------
(,
)
=
SPIn
TVALID
TVALID fCLKSPI
USPI7
USPI8
MISO
SPCK
MOSI
USPI6