Atmel SAM4L Xplained Pro Starter Kit Atmel ATSAM4L-XSTK ATSAM4L-XSTK Data Sheet
Product codes
ATSAM4L-XSTK
652
42023E–SAM–07/2013
ATSAM4L8/L4/L2
25. Picopower UART (PICOUART)
Rev: 1.0.1.0
25.1
Features
•
Ultra low power UART RX line with fixed format :
– 9600 bauds
– 1 start bit
– 8-bit data
– No parity bit
– 1 stop bit
•
Use very low power 32kHz or 1kHz reference clock (Internal RC or Crystal)
•
Event system support and device wake-up source
– start bit detection
– full frame reception
– character recognition
•
All low power modes supported included backup mode
25.2
Overview
The Picopower UART peripheral provides a minimalistic UART RX line feature in any of the low
power modes including backup mode. It allows the device to be waken up from any of low-power
modes by monitoring the RX line. It also able to generate an event to the Peripheral Event Con-
troller (PEVC).
power modes including backup mode. It allows the device to be waken up from any of low-power
modes by monitoring the RX line. It also able to generate an event to the Peripheral Event Con-
troller (PEVC).
The PICOUART is usually associated with another USART in the system, sharing the same
RXD pin. The PICOUART is then used to wake-up the device and the USART provides the full
UART RX/TX feature when the device is waken up
RXD pin. The PICOUART is then used to wake-up the device and the USART provides the full
UART RX/TX feature when the device is waken up
The number of PICOUART modules implemented is device specific. Refer to the Module Config-
uration section for details.
uration section for details.
25.3
Block Diagram
Figure 25-1. PICOUART Block Diagram
P IC O U A R T
R X D
C L K 3 2
P e rip h e ra l
B u s
R H R
R X _F S M
W a ke
B P M
C F G
C R
C L K _P IC O U A R T
P E V C
E ve n t