SAM4L Datasheet, PDF (649/1185 Pages) ATMEL Corporation – ATSAM ARM-based Flash MCU

ATSAM4L4/L2
• One Stop bit
• No parity bit
A frame is valid when it matches exactly with this configuration. Valid received byte is extracted
from the frame and stored in the Receive Holding Register (RHR.CDATA). When a valid data
byte is stored, the Data Ready bit is set to one in the Status Register (SR.DRDY). DRDY is set to
zero when a new start bit is detected.
There is no overrun detection, meaning that RHR value is valid only when DRDY is equal to one.
25.6.2
Wakeup from Power Save Mode
PICOUART is able to wakeup the device from any Power Save Mode including Backup Mode.
The use should first enable the wakeup source by programming the Configuration register
(CFG.SOURCE) and select the source action to be a wake-up by programming the Configura-
tion register (CFG.ACTION) .
There are three wakeup sources:
• Start bit detection: As soon as a start bit is detected , the PICOUART wakes up the device
and normal PICOUART operations are perfomed, leading to DRDY set to one if a valid frame
is finally received.
• Full frame reception: when a valid frame is received, the valid received byte is stored in RHR
and DRDY is set to one. Then the device is waken up
• Character recognition: when a valid frame is received, the valid received byte is stored in
RHR and DRDY is set to one. If the received byte match the data stored in CFG.MATCH,
then the device is waken u.p
Only one wakeup source can be enabled at a time.
25.6.3
Peripheral Event
PICOUART is able to generate an event to the PEVC. The use should first enable the event
source by programming the Configuration register (CFG.SOURCE) and select the source action
to be a wake-up by programming the Configuration register (CFG.ACTION) .
There are three event sources:
• Start bit detection: As soon as a start bit is detected , the PICOUART generates an event and
normal PICOUART operations are perfomed, leading to DRDY set to one if a valid frame is
finally received.
• Full frame reception: when a valid frame is received, the valid received byte is stored in RHR
and DRDY is set to one. Then the event is generated.
• Character recognition: when a valid frame is received, the valid received byte is stored in
RHR and DRDY is set to one. If the received byte match the data stored in CFG.MATCH,
then the event is generated.
Only one even source can be enabled at a time.
42023C–SAM–02/2013
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