It is possible to shut down the RS232C level conversion IC connected to CON3 and CON4 by controlling
[2]
the
BOOT_MODE1 (GPIO4_31) pin on the i.MX257.
5.8 CON3 Signals
Pin Number
Signal Name
I/O
Function
1
DCD2
In
Carrier Detect, connected to the UART1_RTS pin on i.MX257,
signal line shared with CON4 (pin 1)
2
RXD2
In
Receive Data, connected to the UART2_RXD pin on i.MX257,
signal line shared with CON4 (pin 3)
3
TXD2
Out
Transmit Data, connected to UART2_TXD pin on i.MX257,
signal line shared with CON4 (pin 5)
4
DTR2
Out
Data Terminal Ready, connected to UART1_RXD on i.MX257,
signal line shared with CON4 (pin 7)
5
GND
Power
Power (GND)
6
DSR2
In
Data Set Ready, connected to UART1_TXD pin on i.MX257,
signal line shared with CON4 (pin 2)
7
RTS2
Out
Request To Send, connected to UART2_CTS pin on i.MX257,
signal line shared with CON4 (pin 4)
8
CTS2
In
Clear To Send, connected to UART2_RTS pin on i.MX257,
signal line shared with CON4 (pin 6)
9
RI2
In
Ring Indicator, connected to UART1_CTS pin on i.MX257,
signal line shared with CON4 (pin 8)
5.9 CON4 Signals
Pin Number
Signal Name
I/O
Function
1
DCD2
In
Carrier Detect, connected to the UART1_RTS pin on i.MX257,
signal line shared with CON3 (pin 1)
2
DSR2
In
Data Set Ready, connected to UART1_TXD pin on i.MX257,
signal line shared with CON3 (pin 6)
3
RXD2
In
Receive Data, connected to the UART2_RXD pin on i.MX257,
signal line shared with CON3 (pin 2)
4
RTS2
Out
Request To Send, connected to UART2_CTS pin on i.MX257,
signal line shared with CON3 (pin 7)
5
TXD2
Out
Transmit Data, connected to UART2_TXD pin on i.MX257,
signal line shared with CON3 (pin 3)
6
CTS2
In
Clear To Send, connected to UART2_RTS pin on i.MX257,
signal line shared with CON3 (pin 8)
7
DTR2
Out
Data Terminal Ready, connected to UART1_RXD on i.MX257,
signal line shared with CON3 (pin 4)
8
RI2
In
Ring Indicator, connected to UART1_CTS pin on i.MX257,
signal line shared with CON3 (pin 9)
9
GND
Power
Power (GND)
10
+3.3V_CPU
Power
Power (+3.3V_CPU)
[1]
[1]
The combined maximum output current of CON1, CON4, CON7 and CON10 is 200mA.
[2]
After the BOOT_MODE1 (GPIO4_31) pin on i.MX257 is set to GPIO output mode, a low signal will activate shut-down mode and a high signal will
return the IC to normal mode.
Armadillo-400 Series Hardware Manual
Interface Specifications
21
