3.4
Configuration switches
There are configuration switches SW0 and SW1 on the back panel.
This section contains the following subsections:
•
3.4.1 Use of configuration switches
•
3.4.2 Remote UART configuration
3.4.1
Use of configuration switches
The SW0 and SW1 switches affect board initialization.
The
config.txt
configuration file contains
USERSWITCH
and
CONFSWITCH
entries for the virtual switch
register bits SYS_SW[7:0] and SYS_CFGSW[7:0] in the IOFPGA. The configuration system does not
use these virtual switches for system configuration, but they are available for the user application and
boot monitor.
Note
• The default setting for configuration switches SW0 and SW1 is OFF.
• If the switches are in the up position, they are OFF. See
.
Boot script switch SW0
Reserved.
Remote UART control switch SW1
SW1 in the ON position enables UART control and the flow
‑
control signals on UART0 to
control the standby
‑
state. This setting is typically used on test farms.
See the following for information about the configuration switches:
•
.
•
.
3.4.2
Remote UART configuration
To enable remote UART control:
Switch SW1, on the side panel must be ON, and the correct options must be set in the
config.txt
file to
connect the UART0 port to the MCC.
An external controller can toggle the UART0 connector on the side panel
SER0_DSR
, pin 6, HIGH for
100ms to put the N1 SDP into standby
‑
state. This is equivalent to pressing the Hardware Reset button,
PBRESET. Power cycling the board also places the system in the standby state.
Note
The duration of the
SER0_DSR
HIGH pulse must be greater than or equal to 100ms.
Remote UART0 control requires a full null modem cable that Arm supplies with the N1 SDP. The
following figure shows the cable wiring.
3 Configuration
3.4 Configuration switches
101489_0000_02_en
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