Atmel Evaluation Kit AT91SAM9X25-EK AT91SAM9X25-EK Data Sheet
Product codes
AT91SAM9X25-EK
794
SAM9X25 [DATASHEET]
11054E–ATARM–10-Mar-2014
39.6.2 Power Management
The USART is not continuously clocked. The programmer must first enable the USART Clock in the Power Management
Controller (PMC) before using the USART. However, if the application does not require USART operations, the USART
clock can be stopped when not needed and be restarted later. In this case, the USART will resume its operations where
it left off.
Controller (PMC) before using the USART. However, if the application does not require USART operations, the USART
clock can be stopped when not needed and be restarted later. In this case, the USART will resume its operations where
it left off.
Configuring the USART does not require the USART clock to be enabled.
39.6.3 Interrupt
The USART interrupt line is connected on one of the internal sources of the Interrupt Controller. using the USART
interrupt requires the Interrupt Controller to be programmed first. Note that it is not recommended to use the USART
interrupt line in edge sensitive mode.
interrupt requires the Interrupt Controller to be programmed first. Note that it is not recommended to use the USART
interrupt line in edge sensitive mode.
USART3
CTS3
PC25
B
USART3
RTS3
PC24
B
USART3
RXD3
PC23
B
USART3
SCK3
PC26
B
USART3
TXD3
PC22
B
Table 39-3. I/O Lines
Table 39-4. Peripheral IDs
Instance
ID
USART0
5
USART1
6
USART2
7
USART3
8