Atmel Evaluation Kit AT91SAM9M10-G45-EK AT91SAM9M10-G45-EK データシート
製品コード
AT91SAM9M10-G45-EK
472
SAM9M10 [DATASHEET]
6355F–ATARM–12-Mar-13
31.6
Product Dependencies
31.6.1
I/O Lines
The pins used for interfacing the USART may be multiplexed with the PIO lines. The programmer must first pro-
gram the PIO controller to assign the desired USART pins to their peripheral function. If I/O lines of the USART are
not used by the application, they can be used for other purposes by the PIO Controller.
gram the PIO controller to assign the desired USART pins to their peripheral function. If I/O lines of the USART are
not used by the application, they can be used for other purposes by the PIO Controller.
To prevent the TXD line from falling when the USART is disabled, the use of an internal pull up is mandatory. If the
hardware handshaking feature is used, the internal pull up on TXD must also be enabled.
hardware handshaking feature is used, the internal pull up on TXD must also be enabled.
31.6.2
Power Management
The USART is not continuously clocked. The programmer must first enable the USART Clock in the Power Man-
agement 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.
agement 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.
Table 31-3.
I/O Lines
Instance
Signal
I/O Line
Peripheral
USART0
CTS0
PB15
B
USART0
RTS0
PB17
B
USART0
RXD0
PB18
A
USART0
SCK0
PB16
B
USART0
TXD0
PB19
A
USART1
CTS1
PD17
A
USART1
RTS1
PD16
A
USART1
RXD1
PB5
A
USART1
SCK1
PD29
B
USART1
TXD1
PB4
A
USART2
CTS2
PC11
B
USART2
RTS2
PC9
B
USART2
RXD2
PB7
A
USART2
SCK2
PD30
B
USART2
TXD2
PB6
A
USART3
CTS3
PA24
B
USART3
RTS3
PA23
B
USART3
RXD3
PB9
A
USART3
SCK3
PA22
B
USART3
TXD3
PB8
A