Atmel Evaluation Kit AT91SAM9X35-EK AT91SAM9X35-EK Data Sheet
Product codes
AT91SAM9X35-EK
1244
SAM9X35 [DATASHEET]
11055E–ATARM–10-Mar-2014
47.4 Clock Characteristics
47.4.1 Processor Clock Characteristics
Note:
1. For DDR2 usage only, there are no limitations to LP-DDR, SDRAM and mobile SDRAM.
47.4.2 Master Clock Characteristics
The master clock is the maximum clock at which the system is able to run. It is given by the smallest value of the internal
bus clock and EBI clock.
bus clock and EBI clock.
Note:
1. For DDR2 usage only, there are no limitations to LP-DDR, SDRAM and mobile SDRAM.
47.5 Main Oscillator Characteristics
Note:
1. The C
CRYSTAL
value is specified by the crystal manufacturer. In our case, C
CRYSTAL
must be between 15 pF and 20 pF.
All parasitic capacitance, package and board, must be calculated in order to reach 15 pF (minimum targeted load for
the oscillator) by taking into account the internal load C
the oscillator) by taking into account the internal load C
INT
. So, to target the minimum oscillator load of 15 pF, external
capacitance must be: 15 pF - 4 pF = 11 pF which means that 22 pF is the target value (22 pF from XIN to GND and
22 pF from XOUT to GND). If 20 pF load is targeted, the sum of pad, package, board and external capacitances must
be 20 pF - 4 pF = 16 pF which means 32 pF (32 pF from XIN to GND and 32 pF from XOUT to GND).
22 pF from XOUT to GND). If 20 pF load is targeted, the sum of pad, package, board and external capacitances must
be 20 pF - 4 pF = 16 pF which means 32 pF (32 pF from XIN to GND and 32 pF from XOUT to GND).
Table 47-5. Processor Clock Waveform Parameters
Symbol
Parameter
Conditions
Min
Max
Unit
1/(t
CPPCK
)
Processor Clock Frequency
V
DDCORE
= 0.9V, T
A
= 85°C
125
400
MHz
Table 47-6. Master Clock Waveform Parameters
Symbol
Parameter
Conditions
Min
Max
Unit
1/(t
CPMCK
)
Master Clock Frequency
V
DDCORE
= 0.9V, T
A
= 85°C
125
133
MHz
Table 47-7. Main Oscillator Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
1/(t
CPMAIN
)
Crystal Oscillator Frequency
12
16
MHz
C
CRYSTAL
Crystal Load Capacitance
15
20
pF
C
LEXT
External Load Capacitance
C
CRYSTAL
27
pF
C
CRYSTAL
32
pF
Duty Cycle
40
60
%
t
ST
Startup Time
2
ms
I
DDST
Standby Current Consumption
Standby mode
1
µ
A
P
ON
Drive Level
150
µ
W
I
DD ON
Current Dissipation
@ 12 MHz
0.52
0.55
mA
@ 16 MHz
0.7
1.1
mA