Datasheet
77
9166DS–AVR-01/12
AT32UC3C
Note: 1. These values are based on simulation and characterization of other AVR microcontrollers manufactured in the same pro-
cess technology. These values are not covered by test limits in production.
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, SPI7 + SPI8 or SPI10 + SPI11 depending on
CPOL and NCPHA. is the maximum frequency of the CLK_SPI. Refer to the SPI chap-
ter 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, SPI6 or SPI9 depending on CPOL and NCPHA. is the
SPI master setup time. Please refer to the SPI masterdatasheet for . is the maxi-
mum frequency of the SPI pins. Please refer to the I/O Pin Characteristics section for the
maximum frequency of the pins.
7.9.5 TWIM/TWIS Timing
Figure 7-50 shows the TWI-bus timing requirements and the compliance of the device with
them. Some of these requirements (t
r
and t
f
) are met by the device without requiring user inter-
vention. Compliance with the other requirements (t
HD-STA
, t
SU-STA
, t
SU-STO
, t
HD-DAT
, t
SU-DAT-I2C
, t
LOW-
I2C
, t
HIGH
, and f
TWCK
) requires user intervention through appropriate programming of the relevant
Table 7-49. SPI Timing, Slave Mode
(1)
Symbol Parameter Conditions Min Max Units
SPI6 SPCK falling to MISO delay
external
capacitor =
40pF
31 ns
SPI7 MOSI setup time before SPCK rises 0 ns
SPI8 MOSI hold time after SPCK rises 7 ns
SPI9 SPCK rising to MISO delay 32 ns
SPI10 MOSI setup time before SPCK falls 1.5 ns
SPI11 MOSI hold time after SPCK falls 5 ns
SPI12 NPCS setup time before SPCK rises 4 ns
SPI13 NPCS hold time after SPCK falls 2.5 ns
SPI14 NPCS setup time before SPCK falls 3.5 ns
SPI15 NPCS hold time after SPCK rises 2.5 ns
f
SPCKMAX
MIN f
CLKSPI
1
SPIn
------------(,)=
SPIn
f
CLKSPI
f
SPCKMAX
MIN f
PINMAX
1
SPIn t
SETUP
+
------------------------------------(, )=
SPIn
t
SETUP
t
SETUP
f
PINMAX