Datasheet

333
8011O–AVR–07/10
ATmega164P/324P/644P
Figure 25-5. SPI Interface Timing Requirements (Slave Mode)
25.7 2-wire Serial Interface Characteristics
Table 25-10 describes the requirements for devices connected to the 2-wire Serial Bus. The ATmega164P/324P/644P 2-
wire Serial Interface meets or exceeds these requirements under the noted conditions.
Timing symbols refer to Figure 25-6.
MISO
(Data Output)
SCK
(CPOL = 1)
MOSI
(Data Input)
SCK
(CPOL = 0)
SS
MSB LSB
LSBMSB
...
...
10
11 11
1213 14
17
15
9
X
16
Table 25-10. 2-wire Serial Bus Requirements
Symbol Parameter
Condition Min Max Units
V
IL
Input Low-voltage -0.5 0.3V
CC
V
V
IH
Input High-voltage 0.7V
CC
V
CC
+ 0.5
V
hys
(1)
Hysteresis of Schmitt Trigger Inputs 0.05V
CC
(2)
–
V
OL
(1)
Output Low-voltage 3 mA sink current 0 0.4
t
r
(1)
Rise Time for both SDA and SCL 20 + 0.1C
b
(2)(3)
300
nst
of
(1)
Output Fall Time from V
IHmin
to V
ILmax
10 pF < C
b
< 400 pF
(3)
20 + 0.1C
b
(2)(3)
250
t
SP
(1)
Spikes Suppressed by Input Filter 0 50
(2)
I
i
Input Current each I/O Pin 0.1V
CC
< V
i
< 0.9V
CC
-10 10 µA
C
i
(1)
Capacitance for each I/O Pin – 10 pF
f
SCL
SCL Clock Frequency f
CK
(4)
> max(16f
SCL
, 250kHz)
(5)
0 400 kHz
Rp Value of Pull-up resistor
f
SCL
≤ 100 kHz
f
SCL
> 100 kHz
V
CC
0.4V–
3 mA
----------------------------
1000 ns
C
b
---------------------
Ω
V
CC
0.4V–
3 mA
----------------------------
300 ns
C
b
----------------- -