Spi timing characteristics – Rainbow Electronics ATmega3290P_V User Manual
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ATmega329/3290/649/6490
2552H–AVR–11/06
Figure 139. Maximum Frequency vs. V
CC
(8 - 16 MHz).
SPI Timing
Characteristics
See Figure 140 and Figure 141 for details.
Note:
1. In SPI Programming mode the minimum SCK high/low period is:
- 2 t
CLCL
for f
CK
< 12 MHz
- 3 t
CLCL
for f
CK
> 12 MHz
16 MHz
8 MHz
2.7V
4.5V
5.5V
Safe Operating Area
Table 140. SPI Timing Parameters
Description
Mode
Min
Typ
Max
1
SCK period
Master
See Table 75
ns
2
SCK high/low
Master
50% duty cycle
3
Rise/Fall time
Master
3.6
4
Setup
Master
10
5
Hold
Master
10
6
Out to SCK
Master
0.5 • t
sck
7
SCK to out
Master
10
8
SCK to out high
Master
10
9
SS low to out
Slave
15
10
SCK period
Slave
4 • t
ck
11
SCK high/low
(1)
Slave
2 • t
ck
12
Rise/Fall time
Slave
1.6
µs
13
Setup
Slave
10
ns
14
Hold
Slave
t
ck
15
SCK to out
Slave
15
16
SCK to SS high
Slave
20
17
SS high to tri-state
Slave
10
18
SS low to SCK
Slave
20 • t
ck