Datasheet

17
6289CS–ATARM–28-May-09
AT91SAM9R64/RL64
Figure 5-1. Example of PLL and USB Power Supplies
5.2 Programmable I/O Lines Power Supplies
The power supplies pins VDDIOM support two voltage ranges. This allows the device to reach
its maximum speed either out of 1.8V or 3.3V external memories.
The maximum speed is MCK on the pin SDCK (SDRAM Clock) loaded with 30pF for power sup-
ply at 1.8V and 50 pF for power supply at 3.3V.
The maximum speed on the other signals of the External Bus Interface (control, address and
data signals) is 50 MHz.
The voltage ranges are determined by programming registers in the Chip Configuration registers
located in the Matrix User Interface.
At reset, the selected voltage defaults to 3.3V nominal and power supply pins can accept either
1.8V or 3.3V. The user must make sure to program the EBI voltage range before getting the
device out of its Slow Clock Mode.
The PIO lines are supplied through VDDIOP and the speed of the signal that can be driven on
them can reach 50 MHz with 50 pF load.
VIN
CE
VSS
VOUT
ADJ
10µF 0.1µF
10µF
MIC5235YM5
1K
100K
VIN
1V2_USB
0.1µF
1V2_USB
2.2µH
VDDPLLB
0.1µF
1V2_USB
2.2µH
VDDUTMIC
0.1µF
3V3
2.2µH
VDDUTMII