Uart; Usart - Atmel SAM4E-EK User Manual

4.3.6

UART

The Universal Asynchronous Receiver Transmitter features a two-pin UART that can be used for communication and
trace purposes. It offers an ideal channel for in-situ programming solutions. This UART is associated with two PDC
channels to reduce the processor time on packet handling.
This two-pin UART (TXD and RXD only) is buffered through an RS232 Transceiver MN6 and brought to the DB9 male
connector J7.
Figure 4-5. UART.
+3V3
UTXD0
PA10
PA9
URXD0
TP4
4.3.7

USART

The Universal Synchronous/Asynchronous Receiver Transmitter (USART) provides one full duplex universal
synchronous/asynchronous serial link. The data frame format is extensively configurable (data length, parity, number of
stop bits) to support a broad range of serial communication standards. The USART is also associated with PDC
channels for TX/RX data access.
To avoid any electrical conflict, the RS232 and RS485 transceiver are isolated from the receiving line PA21.
•
Chose RS485 channel: Close 1-2 pins on JP11 and set PA23 to high level
•
Chose RS232 channel: Close 2-3 pins on JP11 and set PA23 to low level
Figure 4-6. USART.
PA23
PA22
TXD1
PA21_232
RXD1
PA24
RTS1
PA25
CTS1
+3V3
Downloaded from Elcodis.com electronic components distributor
DBGU
MN7
ADM3202
+3V3
16
VCC
C54
100nF
2
V+
+3V3 C55
6
100nF
V-
C56
R58 R59
100nF
100K 100K
15
GND
11
T1IN
12
R60 0R
R1OUT
10
T2IN
9
R62 0R
R2OUT
TP5
USART1
MN5
+3V3 ADM3312EARU
3
VCC
C43 C45 C44
4.7uF 100nF 100nF
1
V+
21
V-
C48
100nF
23
R38 GND
+3V3
47K
19
SD
5
R37 0R
EN
7
R39 0R
T1IN T1OUT
10
R40 0R
R1OUT R1IN
8
R41 0R
T2IN T2OUT
11
R42 0R
R2OUT R2IN
9
R43 47K
T3IN T3OUT
12
R3OUT R3IN
1
C1+
C53
100nF
3
C1-
4
C2+
C57
100nF
5
C2-
14
T1OUT
13
R1IN
7
T2OUT
8
R2IN
6
C1+
C46
100nF
20
C1-
2
C2+
C47
100nF
4
C2-
24
J5
C3+
1
C49
6
100nF
22 2
C3-
7
18 3
15 8
17 4
14 9
16 5
R44 0R
13
PA21_485
FGND
JP11
PA21
2
PA21_232
J7
1
6
2
7
3
8
4
9
5
FGND
SAM4E-EK User Guide
42067A−SAM4E−01/2013
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