Datasheet

149
42023GS–SAM–03/2014
ATSAM4L8/L4/L2
Where is the MISO delay, SPI6 or SPI9 depending on CPOL and NCPHA. is the
SPI master setup time. refer to the SPI master datasheet for . is the maximum
frequency of the SPI pins. refer to the I/O Pin Characteristics section for the maximum frequency
of the pins.
9.10.4 TWIM/TWIS Timing
Figure 9-64 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-TWI
, t
LOW-
TWI
, t
HIGH
, and f
TWCK
) requires user intervention through appropriate programming of the relevant
TWIM and TWIS user interface registers. refer to the TWIM and TWIS sections for more
information.
Notes: 1. Standard mode: ; fast mode: .
SPIn
t
SETUP
t
SETUP
f
PINMAX
Table 9-64. TWI-Bus Timing Requirements
Symbol Parameter Mode
Minimum Maximum
UnitRequirement Device Requirement Device
t
r
TWCK and TWD rise time
Standard
(1)
- 1000
ns
Fast
(1)
20 + 0.1C
b
300
t
f
TWCK and TWD fall time
Standard - 300
ns
Fast 20 + 0.1C
b
300
t
HD-STA
(Repeated) START hold time
Standard 4
t
clkpb
- μs
Fast 0.6
t
SU-STA
(Repeated) START set-up time
Standard 4.7
t
clkpb
- μs
Fast 0.6
t
SU-STO
STOP set-up time
Standard 4.0
4t
clkpb
- μs
Fast 0.6
t
HD-DAT
Data hold time
Standard
0.3
(2)
2t
clkpb
3.45
()
15t
prescaled
+ t
clkpb
μs
Fast 0.9
()
t
SU-DAT-TWI
Data set-up time
Standard 250
2t
clkpb
-ns
Fast 100
t
SU-DAT
--t
clkpb
--
t
LOW-TWI
TWCK LOW period
Standard 4.7
4t
clkpb
- μs
Fast 1.3
t
LOW
--t
clkpb
--
t
HIGH
TWCK HIGH period
Standard 4.0
8t
clkpb
- μs
Fast 0.6
f
TWCK
TWCK frequency
Standard
-
100
kHz
Fast 400
1
12t
clkpb
------------------------
f
TWCK
100 kHz≤
f
TWCK
100 kHz>